diff --git a/flowbit-backend/core/models.py b/flowbit-backend/core/models.py
index 2dcdacd..45ddd19 100644
--- a/flowbit-backend/core/models.py
+++ b/flowbit-backend/core/models.py
@@ -5,7 +5,8 @@
 from django.db import models, transaction
 from django.contrib.auth.models import User
 from django.contrib.auth.hashers import check_password, identify_hasher, make_password
-from django.db.models import Q, Sum
+from django.db.models import Case, DecimalField, F, Q, Sum, When
+from django.db.models.functions import Coalesce
 from decimal import Decimal
 from django.core.exceptions import ValidationError
 from django.utils import timezone
@@ -1106,17 +1107,8 @@ def total_amount(self):
             transaction__is_refunded=False,
             status=Overflow.STATUS_REFUNDED,
         ).aggregate(total=Sum('refund_amount'))['total'] or Decimal('0.00')
-        returned_overflow_total = Overflow.objects.filter(
-            transaction__ticket=self,
-            transaction__is_refunded=False,
-            status=Overflow.STATUS_TCSO,
-            refunded_at__isnull=False,
-            resolution_type=Overflow.RESOLUTION_REFUND_OVERFLOW,
-        ).aggregate(total=Sum('refund_amount'))['total'] or Decimal('0.00')
 
-        active_total = visible_total - _from_allocation_basis_amount(
-            refunded_overflow_total + returned_overflow_total
-        )
+        active_total = visible_total - _from_allocation_basis_amount(refunded_overflow_total)
         if active_total < Decimal('0.00'):
             return Decimal('0.00')
         return active_total
@@ -1929,7 +1921,123 @@ def _return_reserve_consumed_overflow(overflow, helper_name, refunded_at=None, r
     return matching_overkill
 
 
-def refund_overflow(overflow, helper_name, resolution_type, refunded_at=None):
+def _reduce_transaction_total_for_overflow_refund(overflow):
+    if not overflow.transaction_id:
+        return
+
+    refund_amount = overflow.amount_to_approve or overflow.excess_amount or Decimal('0.00')
+    reduction = _from_allocation_basis_amount(refund_amount)
+    transaction_obj = overflow.transaction
+    next_total = transaction_obj.total_amount - reduction
+    if next_total < Decimal('0.00'):
+        next_total = Decimal('0.00')
+
+    transaction_obj.total_amount = next_total
+    transaction_obj.save(update_fields=['total_amount'])
+    if transaction_obj.ticket_id:
+        transaction_obj.ticket.refresh_refund_state()
+
+
+def _restore_transaction_total_from_active_amounts(transaction_obj):
+    if transaction_obj is None:
+        return
+
+    allocated_total = transaction_obj.allocations.aggregate(
+        total=Sum('amount')
+    )['total'] or Decimal('0.00')
+    active_overflow_total = transaction_obj.overflows.exclude(
+        status=Overflow.STATUS_REFUNDED
+    ).aggregate(
+        total=Sum(
+            Case(
+                When(status=Overflow.STATUS_TCSO, then=F('excess_amount')),
+                default=Coalesce(F('amount_to_approve'), F('excess_amount')),
+                output_field=DecimalField(max_digits=12, decimal_places=2),
+            )
+        )
+    )['total'] or Decimal('0.00')
+
+    restored_total = _from_allocation_basis_amount(allocated_total + active_overflow_total)
+    transaction_obj.total_amount = restored_total
+    transaction_obj.save(update_fields=['total_amount'])
+    if transaction_obj.ticket_id:
+        transaction_obj.ticket.refresh_refund_state()
+
+
+def _move_approved_overflow_to_overkill(
+    overflow,
+    helper_name,
+    refunded_at=None,
+    restore_capacity_adjustment=True,
+    reduce_transaction_total=True,
+):
+    refunded_at = refunded_at or timezone.now()
+    refund_amount = overflow.amount_to_approve or overflow.excess_amount or Decimal('0.00')
+    collaborator_ids = list(overflow.collaborators.values_list('id', flat=True))
+
+    if restore_capacity_adjustment:
+        capacity_refund_amount = (
+            refund_amount
+            if overflow.resolution_type == Overflow.RESOLUTION_RESERVE_CONSUMED
+            else _refund_capacity_amount_for_overflow(overflow)
+        )
+        if capacity_refund_amount > 0:
+            _grant_capacity_adjustment(
+                overflow,
+                capacity_refund_amount,
+                IdentifierCapacityAdjustment.TYPE_REFUND_CSO,
+                helper_name,
+            )
+
+    if reduce_transaction_total:
+        _reduce_transaction_total_for_overflow_refund(overflow)
+
+    matching_overkill = (
+        Overflow.objects.filter(
+            identifier=overflow.identifier,
+            owner=overflow.owner,
+            period=overflow.period,
+            status=Overflow.STATUS_OVERKILL,
+        )
+        .order_by('approved_at', 'id')
+        .first()
+    )
+
+    if matching_overkill:
+        matching_overkill.excess_amount = (matching_overkill.excess_amount or Decimal('0.00')) + refund_amount
+        matching_overkill.amount_to_approve = (matching_overkill.amount_to_approve or Decimal('0.00')) + refund_amount
+        matching_overkill.refunded_at = None
+        matching_overkill.refund_amount = None
+        matching_overkill.transaction = None
+        matching_overkill.save(update_fields=[
+            'excess_amount',
+            'amount_to_approve',
+            'refunded_at',
+            'refund_amount',
+            'transaction',
+        ])
+    else:
+        matching_overkill = Overflow.objects.create(
+            transaction=None,
+            identifier=overflow.identifier,
+            owner=overflow.owner,
+            period=overflow.period,
+            excess_amount=refund_amount,
+            status=Overflow.STATUS_OVERKILL,
+            amount_to_approve=refund_amount,
+            approved_at=overflow.approved_at or refunded_at,
+            helper_name=overflow.helper_name or helper_name,
+            resolution_type=Overflow.RESOLUTION_APPROVE,
+        )
+
+    if collaborator_ids:
+        matching_overkill.collaborators.set(collaborator_ids)
+
+    overflow.delete()
+    return matching_overkill
+
+
+def refund_overflow(overflow, helper_name, resolution_type, refunded_at=None, cso_refund_mode=None):
     refunded_at = refunded_at or timezone.now()
     helper_name = helper_name or DEFAULT_HELPER_NAME
     period = overflow.period
@@ -1946,11 +2054,12 @@ def refund_overflow(overflow, helper_name, resolution_type, refunded_at=None):
             Overflow.RESOLUTION_REFUND_TICKET,
         }
     ):
-        restored_overkill = _return_reserve_consumed_overflow(
+        restored_overkill = _move_approved_overflow_to_overkill(
             overflow,
             helper_name=helper_name,
             refunded_at=refunded_at,
-            restore_capacity_adjustment=resolution_type == Overflow.RESOLUTION_REFUND_OVERFLOW,
+            restore_capacity_adjustment=True,
+            reduce_transaction_total=True,
         )
         if period:
             _retry_pending_overflows(period, restored_overkill.identifier)
@@ -1958,13 +2067,25 @@ def refund_overflow(overflow, helper_name, resolution_type, refunded_at=None):
 
     if resolution_type == Overflow.RESOLUTION_REFUND_OVERFLOW:
         if overflow.status == Overflow.STATUS_CSO:
+            if cso_refund_mode == 'refund_spill_over':
+                restored_overkill = _move_approved_overflow_to_overkill(
+                    overflow,
+                    helper_name=helper_name,
+                    refunded_at=refunded_at,
+                    restore_capacity_adjustment=True,
+                    reduce_transaction_total=True,
+                )
+                if period:
+                    _retry_pending_overflows(period, restored_overkill.identifier)
+                return restored_overkill
+
             overflow.status = Overflow.STATUS_TCSO
             overflow.approved_at = None
-            overflow.refunded_at = refunded_at
-            overflow.refund_amount = overflow.amount_to_approve or overflow.excess_amount
+            overflow.refunded_at = None
+            overflow.refund_amount = None
             overflow.amount_to_approve = None
             overflow.helper_name = helper_name
-            overflow.resolution_type = resolution_type
+            overflow.resolution_type = ''
             overflow.save(update_fields=[
                 'status',
                 'approved_at',
@@ -1975,6 +2096,8 @@ def refund_overflow(overflow, helper_name, resolution_type, refunded_at=None):
                 'resolution_type',
             ])
             overflow.collaborators.clear()
+            if overflow.transaction_id:
+                _restore_transaction_total_from_active_amounts(overflow.transaction)
             if period:
                 _retry_pending_overflows(period, overflow.transaction.identifier)
             return overflow
diff --git a/flowbit-backend/core/serializers.py b/flowbit-backend/core/serializers.py
index eacc604..de9b30e 100644
--- a/flowbit-backend/core/serializers.py
+++ b/flowbit-backend/core/serializers.py
@@ -361,7 +361,6 @@ def _get_overflows(self, obj):
     def get_total_amount(self, obj):
         visible_total = Decimal('0.00')
         refunded_overflow_total = Decimal('0.00')
-        returned_overflow_total = Decimal('0.00')
 
         transactions = self._get_transactions(obj)
         for transaction in transactions:
@@ -375,16 +374,8 @@ def get_total_amount(self, obj):
                 continue
             if overflow.status == Overflow.STATUS_REFUNDED:
                 refunded_overflow_total += overflow.refund_amount or Decimal('0.00')
-            elif (
-                overflow.status == Overflow.STATUS_TCSO
-                and overflow.refunded_at is not None
-                and overflow.resolution_type == Overflow.RESOLUTION_REFUND_OVERFLOW
-            ):
-                returned_overflow_total += overflow.refund_amount or Decimal('0.00')
-
-        active_total = visible_total - _from_allocation_basis_amount(
-            refunded_overflow_total + returned_overflow_total
-        )
+
+        active_total = visible_total - _from_allocation_basis_amount(refunded_overflow_total)
         if active_total < Decimal('0.00'):
             return Decimal('0.00')
         return active_total
@@ -640,6 +631,10 @@ class TicketRefundActionSerializer(serializers.Serializer):
     action = serializers.ChoiceField(choices=['refund_ticket', 'refund_transaction'])
     transaction_id = serializers.IntegerField(required=False)
     sync_repeat_ticket = serializers.BooleanField(required=False, default=False)
+    cso_refund_mode = serializers.ChoiceField(
+        choices=['return_to_tcso', 'refund_spill_over'],
+        required=False,
+    )
     admin_override_code = serializers.CharField(
         write_only=True,
         required=False,
diff --git a/flowbit-backend/core/tests.py b/flowbit-backend/core/tests.py
index ad20fc1..e715367 100644
--- a/flowbit-backend/core/tests.py
+++ b/flowbit-backend/core/tests.py
@@ -3786,6 +3786,140 @@ def test_ticket_total_amount_updates_after_overflow_only_refund(self):
             ).exists()
         )
 
+    def test_ticket_refund_with_cso_can_change_back_to_tcso_without_reducing_total(self):
+        refund_ticket = Ticket.objects.create(
+            customer_name='Ticket CSO Return',
+            created_by=self.approver,
+        )
+        refund_transaction = Transaction.objects.create(
+            ticket=refund_ticket,
+            identifier=self.second_identifier,
+            total_amount=Decimal('400.00'),
+            created_by=self.approver,
+        )
+        overflow = Overflow.objects.get(transaction=refund_transaction, status=Overflow.STATUS_TCSO)
+        self.client.post(
+            f'/api/overflows/{overflow.id}/approve/',
+            {
+                'amount_to_approve': '300.00',
+                'collaborator_ids': [self.collaborator.id],
+            },
+            format='json',
+        )
+
+        response = self.client.post(
+            f'/api/tickets/{refund_ticket.ticket_number}/refund/',
+            {
+                'action': 'refund_ticket',
+                'admin_override_code': 'override-123',
+                'cso_refund_mode': 'return_to_tcso',
+            },
+            format='json',
+        )
+
+        self.assertEqual(response.status_code, status.HTTP_200_OK)
+        refund_ticket.refresh_from_db()
+        refund_transaction.refresh_from_db()
+        overflow.refresh_from_db()
+        self.assertFalse(refund_ticket.is_refunded)
+        self.assertFalse(refund_transaction.is_refunded)
+        self.assertEqual(overflow.status, Overflow.STATUS_TCSO)
+        self.assertEqual(refund_transaction.total_amount, Decimal('400.00'))
+        self.assertEqual(refund_ticket.total_amount, Decimal('400.00'))
+
+        detail_response = self.client.get(f'/api/tickets/{refund_ticket.ticket_number}/')
+        self.assertEqual(detail_response.status_code, status.HTTP_200_OK)
+        self.assertEqual(Decimal(detail_response.data['total_amount']), Decimal('400.00'))
+
+    def test_return_to_tcso_restores_transaction_total_if_old_bug_already_reduced_it(self):
+        refund_ticket = Ticket.objects.create(
+            customer_name='Ticket CSO Restore',
+            created_by=self.approver,
+        )
+        refund_transaction = Transaction.objects.create(
+            ticket=refund_ticket,
+            identifier=self.second_identifier,
+            total_amount=Decimal('400.00'),
+            created_by=self.approver,
+        )
+        overflow = Overflow.objects.get(transaction=refund_transaction, status=Overflow.STATUS_TCSO)
+        self.client.post(
+            f'/api/overflows/{overflow.id}/approve/',
+            {
+                'amount_to_approve': '300.00',
+                'collaborator_ids': [self.collaborator.id],
+            },
+            format='json',
+        )
+
+        refund_transaction.total_amount = Decimal('160.00')
+        refund_transaction.save(update_fields=['total_amount'])
+
+        response = self.client.post(
+            f'/api/tickets/{refund_ticket.ticket_number}/refund/',
+            {
+                'action': 'refund_ticket',
+                'admin_override_code': 'override-123',
+                'cso_refund_mode': 'return_to_tcso',
+            },
+            format='json',
+        )
+
+        self.assertEqual(response.status_code, status.HTTP_200_OK)
+        refund_transaction.refresh_from_db()
+        refund_ticket.refresh_from_db()
+        detail_response = self.client.get(f'/api/tickets/{refund_ticket.ticket_number}/')
+        self.assertEqual(detail_response.status_code, status.HTTP_200_OK)
+        self.assertEqual(refund_transaction.total_amount, Decimal('400.00'))
+        self.assertEqual(Decimal(detail_response.data['total_amount']), Decimal('400.00'))
+
+    def test_ticket_transaction_refund_with_cso_can_refund_spill_over_into_overkill(self):
+        refund_ticket = Ticket.objects.create(
+            customer_name='Transaction CSO Refund',
+            created_by=self.approver,
+        )
+        refund_transaction = Transaction.objects.create(
+            ticket=refund_ticket,
+            identifier=self.second_identifier,
+            total_amount=Decimal('400.00'),
+            created_by=self.approver,
+        )
+        overflow = Overflow.objects.get(transaction=refund_transaction, status=Overflow.STATUS_TCSO)
+        self.client.post(
+            f'/api/overflows/{overflow.id}/approve/',
+            {
+                'amount_to_approve': '300.00',
+                'collaborator_ids': [self.collaborator.id],
+            },
+            format='json',
+        )
+
+        response = self.client.post(
+            f'/api/tickets/{refund_ticket.ticket_number}/refund/',
+            {
+                'action': 'refund_transaction',
+                'transaction_id': refund_transaction.id,
+                'admin_override_code': 'override-123',
+                'cso_refund_mode': 'refund_spill_over',
+            },
+            format='json',
+        )
+
+        self.assertEqual(response.status_code, status.HTTP_200_OK)
+        refund_ticket.refresh_from_db()
+        refund_transaction.refresh_from_db()
+        self.assertFalse(refund_ticket.is_refunded)
+        self.assertFalse(refund_transaction.is_refunded)
+        self.assertEqual(refund_transaction.total_amount, Decimal('160.00'))
+        self.assertEqual(refund_ticket.total_amount, Decimal('160.00'))
+        overkill = Overflow.objects.get(
+            identifier=self.second_identifier,
+            owner=self.approver,
+            period=self.active_period,
+            status=Overflow.STATUS_OVERKILL,
+        )
+        self.assertEqual(overkill.amount_to_approve, Decimal('300.00'))
+
     def test_ticket_refunds_are_blocked_after_period_pre_close(self):
         self.active_period.apply_pre_close(triggered_at=timezone.now(), acting_user=self.approver)
 
@@ -4127,7 +4261,7 @@ def test_direct_overkill_creation_is_blocked_after_period_pre_close(self):
         self.assertEqual(response.status_code, status.HTTP_400_BAD_REQUEST)
         self.assertEqual(response.data['detail'], 'Ticket creation is locked after the pre-close time is reached.')
 
-    def test_returning_cso_overflow_moves_it_back_to_tcso(self):
+    def test_returning_cso_overflow_moves_it_back_to_tcso_without_reducing_total(self):
         tx = Transaction.objects.create(
             ticket=Ticket.objects.create(customer_name='Return CSO Ticket', created_by=self.approver),
             identifier=self.second_identifier,
@@ -4148,18 +4282,25 @@ def test_returning_cso_overflow_moves_it_back_to_tcso(self):
 
         return_response = self.client.post(
             f'/api/overflows/{overflow.id}/resolve/',
-            {'action': 'refund_overflow_only', 'admin_override_code': 'override-123'},
+            {
+                'action': 'refund_overflow_only',
+                'admin_override_code': 'override-123',
+                'cso_refund_mode': 'return_to_tcso',
+            },
             format='json',
         )
 
         self.assertEqual(return_response.status_code, status.HTTP_200_OK)
         overflow.refresh_from_db()
+        tx.refresh_from_db()
         tx.ticket.refresh_from_db()
         self.assertEqual(overflow.status, Overflow.STATUS_TCSO)
         self.assertIsNone(overflow.approved_at)
         self.assertIsNone(overflow.amount_to_approve)
-        self.assertEqual(overflow.refund_amount, Decimal('300.00'))
-        self.assertEqual(tx.ticket.total_amount, Decimal('160.00'))
+        self.assertIsNone(overflow.refunded_at)
+        self.assertIsNone(overflow.refund_amount)
+        self.assertEqual(tx.total_amount, Decimal('400.00'))
+        self.assertEqual(tx.ticket.total_amount, Decimal('400.00'))
         self.assertFalse(
             IdentifierCapacityAdjustment.objects.filter(
                 overflow=overflow,
@@ -4167,6 +4308,48 @@ def test_returning_cso_overflow_moves_it_back_to_tcso(self):
             ).exists()
         )
 
+    def test_refunding_cso_spill_over_moves_it_to_overkill_and_reduces_total(self):
+        tx = Transaction.objects.create(
+            ticket=Ticket.objects.create(customer_name='Refund CSO Ticket', created_by=self.approver),
+            identifier=self.second_identifier,
+            total_amount=Decimal('400.00'),
+            created_by=self.approver,
+        )
+        overflow = Overflow.objects.get(transaction=tx, status=Overflow.STATUS_TCSO)
+
+        self.client.post(
+            f'/api/overflows/{overflow.id}/approve/',
+            {
+                'amount_to_approve': '300.00',
+                'collaborator_ids': [self.collaborator.id],
+            },
+            format='json',
+        )
+
+        refund_response = self.client.post(
+            f'/api/overflows/{overflow.id}/resolve/',
+            {
+                'action': 'refund_overflow_only',
+                'admin_override_code': 'override-123',
+                'cso_refund_mode': 'refund_spill_over',
+            },
+            format='json',
+        )
+
+        self.assertEqual(refund_response.status_code, status.HTTP_200_OK)
+        tx.refresh_from_db()
+        tx.ticket.refresh_from_db()
+        self.assertEqual(tx.total_amount, Decimal('160.00'))
+        self.assertEqual(tx.ticket.total_amount, Decimal('160.00'))
+        overkill = Overflow.objects.get(
+            identifier=self.second_identifier,
+            owner=self.approver,
+            period=self.active_period,
+            status=Overflow.STATUS_OVERKILL,
+        )
+        self.assertEqual(overkill.amount_to_approve, Decimal('300.00'))
+        self.assertEqual(list(overkill.collaborators.values_list('id', flat=True)), [self.collaborator.id])
+
     def test_reapproving_returned_cso_restores_active_total(self):
         tx = Transaction.objects.create(
             ticket=Ticket.objects.create(customer_name='Reapprove CSO Ticket', created_by=self.approver),
@@ -4186,7 +4369,11 @@ def test_reapproving_returned_cso_restores_active_total(self):
         )
         self.client.post(
             f'/api/overflows/{overflow.id}/resolve/',
-            {'action': 'refund_overflow_only', 'admin_override_code': 'override-123'},
+            {
+                'action': 'refund_overflow_only',
+                'admin_override_code': 'override-123',
+                'cso_refund_mode': 'return_to_tcso',
+            },
             format='json',
         )
 
@@ -4201,12 +4388,82 @@ def test_reapproving_returned_cso_restores_active_total(self):
 
         self.assertEqual(reapprove_response.status_code, status.HTTP_200_OK)
         overflow.refresh_from_db()
+        tx.refresh_from_db()
         tx.ticket.refresh_from_db()
         self.assertEqual(overflow.status, Overflow.STATUS_CSO)
         self.assertIsNone(overflow.refunded_at)
         self.assertIsNone(overflow.refund_amount)
+        self.assertEqual(tx.total_amount, Decimal('400.00'))
         self.assertEqual(tx.ticket.total_amount, Decimal('400.00'))
 
+    def test_refund_transaction_on_cso_can_change_back_to_tcso(self):
+        tx = Transaction.objects.create(
+            ticket=Ticket.objects.create(customer_name='Refund Tx CSO Ticket', created_by=self.approver),
+            identifier=self.second_identifier,
+            total_amount=Decimal('400.00'),
+            created_by=self.approver,
+        )
+        overflow = Overflow.objects.get(transaction=tx, status=Overflow.STATUS_TCSO)
+        self.client.post(
+            f'/api/overflows/{overflow.id}/approve/',
+            {
+                'amount_to_approve': '300.00',
+                'collaborator_ids': [self.collaborator.id],
+            },
+            format='json',
+        )
+
+        response = self.client.post(
+            f'/api/overflows/{overflow.id}/resolve/',
+            {
+                'action': 'refund_transaction',
+                'admin_override_code': 'override-123',
+                'cso_refund_mode': 'return_to_tcso',
+            },
+            format='json',
+        )
+
+        self.assertEqual(response.status_code, status.HTTP_200_OK)
+        overflow.refresh_from_db()
+        tx.refresh_from_db()
+        self.assertFalse(tx.is_refunded)
+        self.assertEqual(overflow.status, Overflow.STATUS_TCSO)
+        self.assertEqual(tx.total_amount, Decimal('400.00'))
+
+    def test_refund_ticket_on_cso_can_refund_spill_over_into_overkill(self):
+        tx = Transaction.objects.create(
+            ticket=Ticket.objects.create(customer_name='Refund Ticket CSO Ticket', created_by=self.approver),
+            identifier=self.second_identifier,
+            total_amount=Decimal('400.00'),
+            created_by=self.approver,
+        )
+        overflow = Overflow.objects.get(transaction=tx, status=Overflow.STATUS_TCSO)
+        self.client.post(
+            f'/api/overflows/{overflow.id}/approve/',
+            {
+                'amount_to_approve': '300.00',
+                'collaborator_ids': [self.collaborator.id],
+            },
+            format='json',
+        )
+
+        response = self.client.post(
+            f'/api/overflows/{overflow.id}/resolve/',
+            {
+                'action': 'refund_ticket',
+                'admin_override_code': 'override-123',
+                'cso_refund_mode': 'refund_spill_over',
+            },
+            format='json',
+        )
+
+        self.assertEqual(response.status_code, status.HTTP_200_OK)
+        tx.refresh_from_db()
+        tx.ticket.refresh_from_db()
+        self.assertFalse(tx.is_refunded)
+        self.assertEqual(tx.total_amount, Decimal('160.00'))
+        self.assertEqual(tx.ticket.total_amount, Decimal('160.00'))
+
     def test_returning_overkill_removes_it_and_clears_reserve_capacity(self):
         tx = Transaction.objects.create(
             ticket=Ticket.objects.create(customer_name='Return Overkill Ticket', created_by=self.approver),
diff --git a/flowbit-backend/core/views.py b/flowbit-backend/core/views.py
index 990e767..256265c 100644
--- a/flowbit-backend/core/views.py
+++ b/flowbit-backend/core/views.py
@@ -53,7 +53,6 @@
     LedgerAllocation,
     IdentifierCapacityAdjustment,
     IdentifierLedgerFreeze,
-    _is_returned_pending_overflow,
     _announce_pending_overflows,
     _notify_remaining_overkill_for_lucky_draw,
     _retry_pending_overflows,
@@ -3089,6 +3088,8 @@ def resolve_overflow(self, request, pk=None):
         if action_name in {'', 'approve'}:
             return self._approve_overflow(overflow, request)
 
+        cso_refund_mode = request.data.get('cso_refund_mode')
+
         if action_name in {'refund_overflow_only', 'refund_transaction', 'refund_ticket'}:
             if period_locked_after_lucky_draw(overflow.period):
                 return Response(
@@ -3125,6 +3126,7 @@ def resolve_overflow(self, request, pk=None):
                     overflow,
                     helper_name=helper_name,
                     resolution_type=Overflow.RESOLUTION_REFUND_OVERFLOW,
+                    cso_refund_mode=cso_refund_mode,
                 )
             serializer_data = self.get_serializer(resolved_overflow).data if resolved_overflow is not None else None
             record_audit_log(
@@ -3138,6 +3140,7 @@ def resolve_overflow(self, request, pk=None):
                 ),
                 changes={
                     'resolution_type': Overflow.RESOLUTION_REFUND_OVERFLOW,
+                    'cso_refund_mode': cso_refund_mode or '',
                     'ticket_number': overflow_ticket_number,
                     'transaction_id': overflow_transaction_id,
                     'order_number': overflow_order_number,
@@ -3171,11 +3174,66 @@ def resolve_overflow(self, request, pk=None):
                         generation=repeat_generation,
                     )
             return Response({
-                "message": "Overflow refunded successfully",
+                "message": (
+                    "Overflow changed back to pending successfully"
+                    if cso_refund_mode == 'return_to_tcso'
+                    else "Overflow refunded successfully"
+                ),
                 "overflow": serializer_data,
             }, status=status.HTTP_200_OK)
 
         if action_name == 'refund_transaction':
+            if overflow.status == Overflow.STATUS_CSO and cso_refund_mode in {'return_to_tcso', 'refund_spill_over'}:
+                related_ticket = overflow.transaction.ticket if overflow.transaction_id and overflow.transaction.ticket_id else None
+                with db_transaction.atomic():
+                    refund_overflow(
+                        overflow,
+                        helper_name=helper_name,
+                        resolution_type=Overflow.RESOLUTION_REFUND_OVERFLOW,
+                        cso_refund_mode=cso_refund_mode,
+                    )
+                    if sync_repeat_ticket and related_ticket is not None:
+                        repeat_generation = RepeatTicketGeneration.objects.select_related('repeat_ticket').filter(
+                            ticket=related_ticket
+                        ).first()
+                        if repeat_generation is not None:
+                            _sync_repeat_ticket_from_ticket(
+                                repeat_ticket=repeat_generation.repeat_ticket,
+                                ticket=related_ticket,
+                                generation=repeat_generation,
+                            )
+                record_audit_log(
+                    request,
+                    'overflow.refunded',
+                    target=overflow,
+                    details=f"Resolved CSO refund flow for transaction '{overflow.transaction.order_number}'",
+                    changes={
+                        'resolution_type': Overflow.RESOLUTION_REFUND_TRANSACTION,
+                        'cso_refund_mode': cso_refund_mode,
+                        'ticket_number': overflow.transaction.ticket.ticket_number if overflow.transaction.ticket_id else '',
+                        'transaction_id': overflow.transaction.id,
+                        'order_number': overflow.transaction.order_number,
+                        'identifier_number': overflow.transaction.identifier.number,
+                    },
+                )
+                notify_refund_change(
+                    recipient=overflow.transaction.created_by,
+                    title='Spill over refunded',
+                    message=f"Approved spill over for transaction {overflow.transaction.order_number} was updated.",
+                    request_user=request.user,
+                    action_href='/spill-over',
+                    source_key=f'refund:transaction-cso:{overflow.transaction.id}:{timezone.now().isoformat()}',
+                    period=overflow.period,
+                )
+                refresh_dashboard_for_user(overflow.transaction.created_by)
+                return Response({
+                    "message": (
+                        "Approved spill over moved back to pending successfully"
+                        if cso_refund_mode == 'return_to_tcso'
+                        else "Approved spill over refunded successfully"
+                    ),
+                }, status=status.HTTP_200_OK)
+
             refund_amount = overflow.transaction.total_amount
             related_ticket = overflow.transaction.ticket if overflow.transaction_id and overflow.transaction.ticket_id else None
             with db_transaction.atomic():
@@ -3229,6 +3287,56 @@ def resolve_overflow(self, request, pk=None):
                     status=status.HTTP_400_BAD_REQUEST,
                 )
             ticket = overflow.transaction.ticket
+            if overflow.status == Overflow.STATUS_CSO and cso_refund_mode in {'return_to_tcso', 'refund_spill_over'}:
+                with db_transaction.atomic():
+                    refund_overflow(
+                        overflow,
+                        helper_name=helper_name,
+                        resolution_type=Overflow.RESOLUTION_REFUND_OVERFLOW,
+                        cso_refund_mode=cso_refund_mode,
+                    )
+                    if sync_repeat_ticket:
+                        repeat_generation = RepeatTicketGeneration.objects.select_related('repeat_ticket').filter(
+                            ticket=ticket
+                        ).first()
+                        if repeat_generation is not None:
+                            _sync_repeat_ticket_from_ticket(
+                                repeat_ticket=repeat_generation.repeat_ticket,
+                                ticket=ticket,
+                                generation=repeat_generation,
+                            )
+                record_audit_log(
+                    request,
+                    'overflow.refunded',
+                    target=overflow,
+                    details=f"Resolved CSO refund flow for ticket '{ticket.ticket_number}'",
+                    changes={
+                        'resolution_type': Overflow.RESOLUTION_REFUND_TICKET,
+                        'cso_refund_mode': cso_refund_mode,
+                        'ticket_number': ticket.ticket_number,
+                        'transaction_id': overflow.transaction.id,
+                        'order_number': overflow.transaction.order_number,
+                        'identifier_number': overflow.transaction.identifier.number,
+                    },
+                )
+                notify_refund_change(
+                    recipient=ticket.created_by,
+                    title='Spill over refunded',
+                    message=f"Approved spill over on ticket {ticket.ticket_number} was updated.",
+                    request_user=request.user,
+                    action_href='/spill-over',
+                    source_key=f'refund:ticket-cso:{ticket.id}:{timezone.now().isoformat()}',
+                    period=overflow.period,
+                )
+                refresh_dashboard_for_user(ticket.created_by)
+                return Response({
+                    "message": (
+                        "Approved spill over moved back to pending successfully"
+                        if cso_refund_mode == 'return_to_tcso'
+                        else "Approved spill over refunded successfully"
+                    ),
+                }, status=status.HTTP_200_OK)
+
             refund_summary = _ticket_refund_summary(ticket)
 
             with db_transaction.atomic():
@@ -5214,16 +5322,6 @@ def get_queryset(self):
             total=Sum('refund_amount'),
         ).values('total')[:1]
 
-        returned_overflow_total_subquery = Overflow.objects.filter(
-            transaction__ticket=OuterRef('pk'),
-            transaction__is_refunded=False,
-            status=Overflow.STATUS_TCSO,
-            refunded_at__isnull=False,
-            resolution_type=Overflow.RESOLUTION_REFUND_OVERFLOW,
-        ).values('transaction__ticket').annotate(
-            total=Sum('refund_amount'),
-        ).values('total')[:1]
-
         queryset = queryset.annotate(
             ticket_transaction_count=Count('transactions', distinct=True),
             active_spill_over_count_annotated=Count(
@@ -5251,11 +5349,6 @@ def get_queryset(self):
                 Value(Decimal('0.00')),
                 output_field=DecimalField(max_digits=14, decimal_places=2),
             ),
-            returned_overflow_total_annotated=Coalesce(
-                Subquery(returned_overflow_total_subquery),
-                Value(Decimal('0.00')),
-                output_field=DecimalField(max_digits=14, decimal_places=2),
-            ),
         ).prefetch_related(ticket_transactions).distinct()
 
         queryset = queryset.annotate(
@@ -5263,7 +5356,7 @@ def get_queryset(self):
                 Value(Decimal('0.00')),
                 ExpressionWrapper(
                     F('visible_total_amount_annotated') - ExpressionWrapper(
-                        (F('refunded_overflow_total_annotated') + F('returned_overflow_total_annotated')) / Value(Decimal('1.25')),
+                        F('refunded_overflow_total_annotated') / Value(Decimal('1.25')),
                         output_field=DecimalField(max_digits=14, decimal_places=2),
                     ),
                     output_field=DecimalField(max_digits=14, decimal_places=2),
@@ -5380,6 +5473,7 @@ def post(self, request, ticket_number):
         helper_name = helper_name_from_request(request)
         action_name = validated['action']
         sync_repeat_ticket = validated.get('sync_repeat_ticket', False)
+        cso_refund_mode = validated.get('cso_refund_mode')
 
         if action_name == 'refund_ticket':
             transactions = list(ticket.transactions.all())
@@ -5388,6 +5482,61 @@ def post(self, request, ticket_number):
                     {"detail": "This ticket has already been refunded."},
                     status=status.HTTP_400_BAD_REQUEST,
                 )
+
+            cso_overflows = [
+                overflow
+                for transaction in transactions
+                for overflow in transaction.overflows.all()
+                if overflow.status == Overflow.STATUS_CSO
+            ]
+            if cso_overflows and cso_refund_mode in {'return_to_tcso', 'refund_spill_over'}:
+                with db_transaction.atomic():
+                    for overflow in cso_overflows:
+                        refund_overflow(
+                            overflow,
+                            helper_name=helper_name,
+                            resolution_type=Overflow.RESOLUTION_REFUND_OVERFLOW,
+                            cso_refund_mode=cso_refund_mode,
+                        )
+                    if sync_repeat_ticket:
+                        repeat_generation = RepeatTicketGeneration.objects.select_related('repeat_ticket').filter(
+                            ticket=ticket
+                        ).first()
+                        if repeat_generation is not None:
+                            _sync_repeat_ticket_from_ticket(
+                                repeat_ticket=repeat_generation.repeat_ticket,
+                                ticket=ticket,
+                                generation=repeat_generation,
+                            )
+
+                record_audit_log(
+                    request,
+                    'ticket.refunded',
+                    target=ticket,
+                    details=f"Resolved CSO refund flow for ticket '{ticket.ticket_number}'",
+                    changes={
+                        'resolution_type': Overflow.RESOLUTION_REFUND_TICKET,
+                        'cso_refund_mode': cso_refund_mode,
+                    },
+                )
+                notify_refund_change(
+                    recipient=ticket.created_by,
+                    title='Spill over refunded',
+                    message=f"Approved spill over on ticket {ticket.ticket_number} was updated.",
+                    request_user=request.user,
+                    action_href='/tickets',
+                    source_key=f'ticket-cso-refund:{ticket.id}:{timezone.now().isoformat()}',
+                    period=ticket.transactions.first().period if ticket.transactions.exists() else None,
+                )
+                refresh_dashboard_for_user(ticket.created_by)
+                return Response({
+                    "message": (
+                        f"Approved spill over on ticket '{ticket.ticket_number}' moved back to pending successfully"
+                        if cso_refund_mode == 'return_to_tcso'
+                        else f"Approved spill over on ticket '{ticket.ticket_number}' refunded successfully"
+                    ),
+                }, status=status.HTTP_200_OK)
+
             refund_summary = _ticket_refund_summary(ticket)
 
             with db_transaction.atomic():
@@ -5443,6 +5592,61 @@ def post(self, request, ticket_number):
                 status=status.HTTP_400_BAD_REQUEST,
             )
 
+        cso_overflows = [
+            overflow for overflow in transaction_obj.overflows.all() if overflow.status == Overflow.STATUS_CSO
+        ]
+        if cso_overflows and cso_refund_mode in {'return_to_tcso', 'refund_spill_over'}:
+            with db_transaction.atomic():
+                for overflow in cso_overflows:
+                    refund_overflow(
+                        overflow,
+                        helper_name=helper_name,
+                        resolution_type=Overflow.RESOLUTION_REFUND_OVERFLOW,
+                        cso_refund_mode=cso_refund_mode,
+                    )
+                if sync_repeat_ticket:
+                    repeat_generation = RepeatTicketGeneration.objects.select_related('repeat_ticket').filter(
+                        ticket=ticket
+                    ).first()
+                    if repeat_generation is not None:
+                        _sync_repeat_ticket_from_ticket(
+                            repeat_ticket=repeat_generation.repeat_ticket,
+                            ticket=ticket,
+                            generation=repeat_generation,
+                        )
+
+            record_audit_log(
+                request,
+                'transaction.refunded',
+                target=transaction_obj,
+                details=f"Resolved CSO refund flow for transaction '{transaction_obj.order_number}'",
+                changes={
+                    'resolution_type': Overflow.RESOLUTION_REFUND_TRANSACTION,
+                    'cso_refund_mode': cso_refund_mode,
+                    'ticket_number': ticket.ticket_number,
+                    'transaction_id': transaction_obj.id,
+                    'order_number': transaction_obj.order_number,
+                    'identifier_number': transaction_obj.identifier.number,
+                },
+            )
+            notify_refund_change(
+                recipient=ticket.created_by,
+                title='Spill over refunded',
+                message=f"Approved spill over for transaction {transaction_obj.order_number} on ticket {ticket.ticket_number} was updated.",
+                request_user=request.user,
+                action_href='/tickets',
+                source_key=f'ticket-transaction-cso-refund:{transaction_obj.id}:{timezone.now().isoformat()}',
+                period=transaction_obj.period,
+            )
+            refresh_dashboard_for_user(ticket.created_by)
+            return Response({
+                "message": (
+                    f"Approved spill over for transaction '{transaction_obj.order_number}' moved back to pending successfully"
+                    if cso_refund_mode == 'return_to_tcso'
+                    else f"Approved spill over for transaction '{transaction_obj.order_number}' refunded successfully"
+                ),
+            }, status=status.HTTP_200_OK)
+
         with db_transaction.atomic():
             refund_transactions(
                 [transaction_obj],
@@ -5499,21 +5703,12 @@ def _ticket_visible_total(ticket):
 
 def _transaction_visible_request_amount(transaction_obj):
     refunded_overflow_total = Decimal('0.00')
-    returned_overflow_total = Decimal('0.00')
 
     for overflow in transaction_obj.overflows.all():
         if overflow.status == Overflow.STATUS_REFUNDED:
             refunded_overflow_total += overflow.refund_amount or Decimal('0.00')
-        elif (
-            overflow.status == Overflow.STATUS_TCSO
-            and overflow.refunded_at is not None
-            and overflow.resolution_type == Overflow.RESOLUTION_REFUND_OVERFLOW
-        ):
-            returned_overflow_total += overflow.refund_amount or Decimal('0.00')
 
-    active_total = transaction_obj.total_amount - _from_allocation_basis_amount(
-        refunded_overflow_total + returned_overflow_total
-    )
+    active_total = transaction_obj.total_amount - _from_allocation_basis_amount(refunded_overflow_total)
     if active_total < Decimal('0.00'):
         return Decimal('0.00')
     return active_total
@@ -5531,7 +5726,7 @@ def _ticket_visible_line_amount(transaction_obj):
     active_overflows = [
         overflow
         for overflow in transaction_obj.overflows.all()
-        if overflow.status != Overflow.STATUS_REFUNDED and not _is_returned_pending_overflow(overflow)
+        if overflow.status != Overflow.STATUS_REFUNDED
     ]
     overflow_total = sum(
         (
diff --git a/flowbit-frontend/src/components/overflow/spill-over-page.tsx b/flowbit-frontend/src/components/overflow/spill-over-page.tsx
index 3947edc..0f56f2f 100644
--- a/flowbit-frontend/src/components/overflow/spill-over-page.tsx
+++ b/flowbit-frontend/src/components/overflow/spill-over-page.tsx
@@ -99,6 +99,14 @@ function sanitizeWholeNumberInput(value: string) {
   return value.replace(/[^\d]/g, "");
 }
 
+function parseWholeNumberInput(value: string) {
+  const normalized = sanitizeWholeNumberInput(value);
+  if (!normalized) {
+    return NaN;
+  }
+  return Number(normalized);
+}
+
 function normalizeIdentifierNumber(value: string) {
   const digits = value.replace(/\D/g, "");
   if (!digits) {
@@ -211,6 +219,11 @@ export function SpillOverPage() {
   const [refundTarget, setRefundTarget] = useState<{
     overflow: FlowBitOverflow;
     action: RefundAction;
+    csoRefundMode?: "return_to_tcso" | "refund_spill_over";
+  } | null>(null);
+  const [pendingCsoRefundChoice, setPendingCsoRefundChoice] = useState<{
+    overflow: FlowBitOverflow;
+    action: RefundAction;
   } | null>(null);
   const [pendingExtraApproval, setPendingExtraApproval] = useState<{
     overflowAmount: number;
@@ -237,7 +250,7 @@ export function SpillOverPage() {
   } | null>(null);
 
   const effectiveUserRole = currentUserState?.user?.role ?? user?.role ?? "";
-  const requiresOverride = effectiveUserRole !== "admin";
+  const requiresOverride = true;
 
   useEffect(() => {
     setUser(getStoredUser());
@@ -334,7 +347,13 @@ export function SpillOverPage() {
 
   function openApproveModal(overflow: FlowBitOverflow) {
     setApproveTarget(overflow);
-    setApproveAmount(formatWholeAmount(overflow.amount_to_approve || overflow.excess_amount || ""));
+    const rawApproveAmount = overflow.amount_to_approve || overflow.excess_amount || "";
+    const parsedApproveAmount = Number(String(rawApproveAmount).replace(/,/g, ""));
+    setApproveAmount(
+      Number.isNaN(parsedApproveAmount) || parsedApproveAmount <= 0
+        ? ""
+        : formatWholeAmount(String(parsedApproveAmount)),
+    );
     const initialCollaboratorId = overflow.collaborators[0];
     setSelectedCollaboratorIds(initialCollaboratorId ? [initialCollaboratorId] : []);
     setEditingCollaboratorId(null);
@@ -376,7 +395,10 @@ export function SpillOverPage() {
     }
 
     const overflowAmount = Number(approveTarget.excess_amount || "0");
-    const nextApproveAmount = Number(approveAmount.trim() || overflowAmount);
+    const parsedApproveAmount = parseWholeNumberInput(approveAmount);
+    const nextApproveAmount = Number.isNaN(parsedApproveAmount)
+      ? overflowAmount
+      : parsedApproveAmount;
     if (nextApproveAmount > overflowAmount) {
       setPendingExtraApproval({
         overflowAmount,
@@ -473,7 +495,7 @@ export function SpillOverPage() {
     try {
       const response = await approveOverflow({
         overflowId: approveTarget.id,
-        amountToApprove: approveAmount.trim() || undefined,
+        amountToApprove: sanitizeWholeNumberInput(approveAmount) || undefined,
         collaboratorIds: selectedCollaboratorIds,
       });
       setToast({ type: "success", message: response.message });
@@ -531,19 +553,29 @@ export function SpillOverPage() {
       return;
     }
 
+    const relatedTicketNumber = refundTarget.overflow.ticket_number;
     setBusyLabel("Processing refund");
     try {
       const response = await resolveOverflowAction({
         overflowId: refundTarget.overflow.id,
         action: refundTarget.action,
         adminOverrideCode: requiresOverride ? overrideCode : undefined,
+        csoRefundMode: refundTarget.csoRefundMode,
         syncRepeatTicket: syncRepeatTicketRefund,
       });
       setToast({ type: "success", message: response.message });
       setRefundTarget(null);
+      setPendingCsoRefundChoice(null);
       setOverrideCode("");
       setSyncRepeatTicketRefund(false);
       await loadPageData();
+      if (
+        relatedTicketNumber &&
+        selectedTicketDetail?.ticket_number === relatedTicketNumber
+      ) {
+        const refreshedTicketDetail = await fetchTicketDetail(relatedTicketNumber);
+        setSelectedTicketDetail(refreshedTicketDetail);
+      }
       notifyDashboardUpdated();
     } catch (error) {
       const message = error instanceof Error ? error.message : "Request failed.";
@@ -553,6 +585,17 @@ export function SpillOverPage() {
     }
   }
 
+  function queueRefundAction(overflow: FlowBitOverflow, action: RefundAction) {
+    if (overflow.status === "CSO") {
+      setRefundPickerTarget(null);
+      setPendingCsoRefundChoice({ overflow, action });
+      return;
+    }
+
+    setRefundPickerTarget(null);
+    setRefundTarget({ overflow, action });
+  }
+
   async function openTicketView(ticketNumber: string | null) {
     if (!ticketNumber) {
       return;
@@ -859,7 +902,10 @@ export function SpillOverPage() {
                   inputMode="numeric"
                   pattern="[0-9]*"
                   value={approveAmount}
-                  onChange={(event) => setApproveAmount(sanitizeWholeNumberInput(event.target.value))}
+                  onChange={(event) => {
+                    const normalized = sanitizeWholeNumberInput(event.target.value);
+                    setApproveAmount(normalized ? formatWholeAmount(normalized) : "");
+                  }}
                   placeholder={formatAmount(approveTarget.excess_amount)}
                 />
               </label>
@@ -1035,6 +1081,7 @@ export function SpillOverPage() {
         onCodeChange={setOverrideCode}
         onCancel={() => {
           setRefundTarget(null);
+          setPendingCsoRefundChoice(null);
           setOverrideCode("");
           setSyncRepeatTicketRefund(false);
         }}
@@ -1053,6 +1100,69 @@ export function SpillOverPage() {
           </label>
         ) : null}
       </AdminConfirmModal>
+
+      {pendingCsoRefundChoice ? (
+        <div
+          className="fixed inset-0 z-[72] flex items-center justify-center bg-stone-950/30 px-4"
+          onClick={() => setPendingCsoRefundChoice(null)}
+        >
+          <div
+            className="w-full max-w-xl rounded-[28px] border border-stone-900/8 bg-white p-5 shadow-[0_18px_48px_rgba(24,24,24,0.18)] sm:p-6"
+            onClick={(event) => event.stopPropagation()}
+          >
+            <p className="text-[12px] font-semibold uppercase tracking-[0.18em] text-stone-500">Approved spill-over</p>
+            <h2 className="mt-2 text-2xl font-semibold text-stone-950">{pendingCsoRefundChoice.overflow.identifier_number}</h2>
+            <p className="mt-2 text-sm leading-6 text-stone-500">
+              This spill-over is currently approved. Choose whether you want to move it back to pending `TCSO` or refund the approved spill-over amount into overkill.
+            </p>
+            <div className="mt-5 space-y-3">
+              <button
+                type="button"
+                className="flex w-full items-center justify-between rounded-[22px] border border-stone-900/8 bg-stone-50 px-4 py-4 text-left transition hover:border-stone-900/20"
+                onClick={() => {
+                  setPendingCsoRefundChoice(null);
+                  setRefundTarget({
+                    overflow: pendingCsoRefundChoice.overflow,
+                    action: pendingCsoRefundChoice.action,
+                    csoRefundMode: "return_to_tcso",
+                  });
+                }}
+              >
+                <div>
+                  <p className="font-semibold text-stone-950">Change back to TCSO</p>
+                  <p className="mt-1 text-sm text-stone-500">
+                    Keep the transaction amount unchanged and move this approved spill-over back to pending.
+                  </p>
+                </div>
+              </button>
+              <button
+                type="button"
+                className="flex w-full items-center justify-between rounded-[22px] border border-stone-900/8 bg-stone-50 px-4 py-4 text-left transition hover:border-stone-900/20"
+                onClick={() => {
+                  setPendingCsoRefundChoice(null);
+                  setRefundTarget({
+                    overflow: pendingCsoRefundChoice.overflow,
+                    action: pendingCsoRefundChoice.action,
+                    csoRefundMode: "refund_spill_over",
+                  });
+                }}
+              >
+                <div>
+                  <p className="font-semibold text-stone-950">Refund spill-over</p>
+                  <p className="mt-1 text-sm text-stone-500">
+                    Move the approved spill-over amount into overkill and reduce the active ticket amount.
+                  </p>
+                </div>
+              </button>
+            </div>
+            <div className="mt-5 flex justify-end">
+              <Button variant="outline" onClick={() => setPendingCsoRefundChoice(null)}>
+                Cancel
+              </Button>
+            </div>
+          </div>
+        </div>
+      ) : null}
       {selectedCollaborator ? (
         <div
           className="fixed inset-0 z-50 flex items-center justify-center bg-stone-950/30 px-4"
@@ -1268,8 +1378,7 @@ export function SpillOverPage() {
                 type="button"
                 className="flex w-full items-center justify-between rounded-[22px] border border-stone-900/8 bg-stone-50 px-4 py-4 text-left transition hover:border-stone-900/20"
                 onClick={() => {
-                  setRefundPickerTarget(null);
-                  setRefundTarget({ overflow: refundPickerTarget, action: "refund_overflow_only" });
+                  queueRefundAction(refundPickerTarget, "refund_overflow_only");
                 }}
               >
                 <div>
@@ -1285,8 +1394,7 @@ export function SpillOverPage() {
                     type="button"
                     className="flex w-full items-center justify-between rounded-[22px] border border-stone-900/8 bg-stone-50 px-4 py-4 text-left transition hover:border-stone-900/20"
                     onClick={() => {
-                      setRefundPickerTarget(null);
-                      setRefundTarget({ overflow: refundPickerTarget, action: "refund_transaction" });
+                      queueRefundAction(refundPickerTarget, "refund_transaction");
                     }}
                   >
                     <div>
@@ -1300,8 +1408,7 @@ export function SpillOverPage() {
                     type="button"
                     className="flex w-full items-center justify-between rounded-[22px] border border-stone-900/8 bg-stone-50 px-4 py-4 text-left transition hover:border-stone-900/20"
                     onClick={() => {
-                      setRefundPickerTarget(null);
-                      setRefundTarget({ overflow: refundPickerTarget, action: "refund_ticket" });
+                      queueRefundAction(refundPickerTarget, "refund_ticket");
                     }}
                   >
                     <div>
diff --git a/flowbit-frontend/src/components/period/period-page.tsx b/flowbit-frontend/src/components/period/period-page.tsx
index fe2ab0d..8781fd5 100644
--- a/flowbit-frontend/src/components/period/period-page.tsx
+++ b/flowbit-frontend/src/components/period/period-page.tsx
@@ -526,7 +526,7 @@ export function PeriodPage() {
                 ? "Delete period"
                 : "Save changes"
         }
-        showCodeInput={false}
+        showCodeInput={true}
         busy={isSaving}
         onCodeChange={setOverrideCode}
         onCancel={() => {
diff --git a/flowbit-frontend/src/components/tickets/ticket-history-page.tsx b/flowbit-frontend/src/components/tickets/ticket-history-page.tsx
index ed55911..99c362f 100644
--- a/flowbit-frontend/src/components/tickets/ticket-history-page.tsx
+++ b/flowbit-frontend/src/components/tickets/ticket-history-page.tsx
@@ -260,7 +260,11 @@ export function TicketHistoryPage() {
     }
   }
 
-  async function runOverflowRefundAction(overflowId: number, kind: "overflow") {
+  async function runOverflowRefundAction(
+    overflowId: number,
+    kind: "overflow",
+    csoRefundMode?: "return_to_tcso" | "refund_spill_over",
+  ) {
     if (!adminOverrideCode.trim()) {
       setToast({
         type: "error",
@@ -275,6 +279,7 @@ export function TicketHistoryPage() {
         overflowId,
         action: "refund_overflow_only",
         adminOverrideCode: adminOverrideCode.trim() || undefined,
+        csoRefundMode,
         syncRepeatTicket,
       });
       await refreshTicketHistoryState();
@@ -299,6 +304,7 @@ export function TicketHistoryPage() {
     action: "refund_ticket" | "refund_transaction",
     kind: "ticket" | "transaction",
     transactionId?: number,
+    csoRefundMode?: "return_to_tcso" | "refund_spill_over",
   ) {
     if (!selectedTicketNumber) {
       return;
@@ -320,6 +326,7 @@ export function TicketHistoryPage() {
         action,
         transactionId,
         adminOverrideCode: adminOverrideCode.trim() || undefined,
+        csoRefundMode,
         syncRepeatTicket,
       });
       await refreshTicketHistoryState();
@@ -565,16 +572,19 @@ export function TicketHistoryPage() {
           setAdminOverrideCode("");
           setSyncRepeatTicket(false);
         }}
-        onRefundTicket={() => runTicketRefundAction("refund_ticket", "ticket")}
-        onRefundTransaction={(transactionId) =>
+        onRefundTicket={(csoRefundMode) =>
+          runTicketRefundAction("refund_ticket", "ticket", undefined, csoRefundMode)
+        }
+        onRefundTransaction={(transactionId, csoRefundMode) =>
           runTicketRefundAction(
             "refund_transaction",
             "transaction",
             transactionId,
+            csoRefundMode,
           )
         }
-        onRefundOverflow={(overflowId) =>
-          runOverflowRefundAction(overflowId, "overflow")
+        onRefundOverflow={(overflowId, csoRefundMode) =>
+          runOverflowRefundAction(overflowId, "overflow", csoRefundMode)
         }
       />
 
diff --git a/flowbit-frontend/src/components/tickets/ticket-refund-modal.tsx b/flowbit-frontend/src/components/tickets/ticket-refund-modal.tsx
index d8727ec..f6305fc 100644
--- a/flowbit-frontend/src/components/tickets/ticket-refund-modal.tsx
+++ b/flowbit-frontend/src/components/tickets/ticket-refund-modal.tsx
@@ -19,9 +19,15 @@ type TicketRefundModalProps = {
   onCodeChange: (value: string) => void;
   onSyncRepeatTicketChange: (value: boolean) => void;
   onClose: () => void;
-  onRefundTicket: () => void;
-  onRefundTransaction: (transactionId: number) => void;
-  onRefundOverflow: (overflowId: number) => void;
+  onRefundTicket: (csoRefundMode?: "return_to_tcso" | "refund_spill_over") => void;
+  onRefundTransaction: (
+    transactionId: number,
+    csoRefundMode?: "return_to_tcso" | "refund_spill_over",
+  ) => void;
+  onRefundOverflow: (
+    overflowId: number,
+    csoRefundMode?: "return_to_tcso" | "refund_spill_over",
+  ) => void;
 };
 
 function formatAmount(value: string) {
@@ -37,9 +43,9 @@ function formatAmount(value: string) {
 }
 
 type ConfirmRefundAction =
-  | { kind: "ticket"; label: string }
-  | { kind: "transaction"; id: number; label: string }
-  | { kind: "overflow"; id: number; label: string };
+  | { kind: "ticket"; label: string; requiresCsoChoice?: boolean }
+  | { kind: "transaction"; id: number; label: string; requiresCsoChoice?: boolean }
+  | { kind: "overflow"; id: number; label: string; requiresCsoChoice?: boolean };
 
 export function TicketRefundModal({
   open,
@@ -73,14 +79,19 @@ export function TicketRefundModal({
       })),
   );
   const [confirmAction, setConfirmAction] = useState<ConfirmRefundAction | null>(null);
+  const [csoRefundMode, setCsoRefundMode] = useState<
+    "return_to_tcso" | "refund_spill_over" | ""
+  >("");
 
   function closeModal() {
     setConfirmAction(null);
+    setCsoRefundMode("");
     onClose();
   }
 
   function openConfirmation(action: ConfirmRefundAction) {
     setConfirmAction(action);
+    setCsoRefundMode("");
   }
 
   function handleConfirmRefund() {
@@ -93,27 +104,28 @@ export function TicketRefundModal({
     }
 
     if (confirmAction.kind === "ticket") {
-      onRefundTicket();
+      onRefundTicket(csoRefundMode || undefined);
       return;
     }
 
     if (confirmAction.kind === "transaction") {
-      onRefundTransaction(confirmAction.id);
+      onRefundTransaction(confirmAction.id, csoRefundMode || undefined);
       return;
     }
 
-    onRefundOverflow(confirmAction.id);
+    onRefundOverflow(confirmAction.id, csoRefundMode || undefined);
   }
 
   return (
-    <div
-      className="fixed inset-0 z-50 flex items-center justify-center bg-stone-950/30 px-4"
-      onClick={closeModal}
-    >
+    <>
       <div
-        className="relative max-h-[90vh] w-full max-w-2xl overflow-y-auto rounded-[28px] border border-stone-900/8 bg-white p-5 shadow-[0_18px_48px_rgba(24,24,24,0.18)] sm:p-6"
-        onClick={(event) => event.stopPropagation()}
+        className="fixed inset-0 z-50 flex items-center justify-center bg-stone-950/30 px-4"
+        onClick={closeModal}
       >
+        <div
+          className="relative max-h-[90vh] w-full max-w-2xl overflow-y-auto rounded-[28px] border border-stone-900/8 bg-white p-5 shadow-[0_18px_48px_rgba(24,24,24,0.18)] sm:p-6"
+          onClick={(event) => event.stopPropagation()}
+        >
         <p className="text-[12px] font-semibold uppercase tracking-[0.18em] text-stone-500">
           Refund
         </p>
@@ -124,21 +136,6 @@ export function TicketRefundModal({
           Choose whether to refund the full ticket, a transaction, or a single spill-over item.
         </p>
 
-        {requireOverrideCode ? (
-          <label className="mt-5 block space-y-2">
-            <span className="text-xs font-semibold uppercase tracking-[0.16em] text-stone-500">
-              Admin override code
-            </span>
-            <Input
-              type="password"
-              value={adminOverrideCode}
-              onChange={(event) => onCodeChange(event.target.value)}
-              placeholder="Enter override code"
-              disabled={Boolean(busyAction)}
-            />
-          </label>
-        ) : null}
-
         {ticket.repeat_ticket_id ? (
           <label className="mt-5 flex items-start gap-3 rounded-[20px] border border-stone-900/8 bg-stone-50 px-4 py-3 text-sm text-stone-600">
             <input
@@ -165,11 +162,14 @@ export function TicketRefundModal({
                 variant="outline"
                 className="rounded-[18px]"
                 onClick={() =>
-                  openConfirmation({
-                    kind: "ticket",
-                    label: `Refund the full ticket ${ticket.ticket_number}`,
-                  })
-                }
+                      openConfirmation({
+                        kind: "ticket",
+                        label: `Refund the full ticket ${ticket.ticket_number}`,
+                        requiresCsoChoice: ticket.transactions.some((transaction) =>
+                          transaction.overflows.some((overflow) => overflow.status === "CSO"),
+                        ),
+                      })
+                    }
                 disabled={Boolean(busyAction)}
               >
                 {busyAction?.kind === "ticket" ? "Refunding..." : "Refund ticket"}
@@ -209,6 +209,9 @@ export function TicketRefundModal({
                         kind: "transaction",
                         id: transaction.id,
                         label: `Refund transaction ${transaction.order_number}`,
+                        requiresCsoChoice: transaction.overflows.some(
+                          (overflow) => overflow.status === "CSO",
+                        ),
                       })
                     }
                     disabled={Boolean(busyAction)}
@@ -253,6 +256,7 @@ export function TicketRefundModal({
                         kind: "overflow",
                         id: overflow.id,
                         label: `Refund spill over for ${overflow.identifierNumber}`,
+                        requiresCsoChoice: overflow.status === "CSO",
                       })
                     }
                     disabled={Boolean(busyAction)}
@@ -267,63 +271,107 @@ export function TicketRefundModal({
           </div>
         ) : null}
 
-        <div className="mt-5 flex justify-end">
-          <Button variant="outline" onClick={closeModal} disabled={Boolean(busyAction)}>
-            Close
-          </Button>
+          <div className="mt-5 flex justify-end">
+            <Button variant="outline" onClick={closeModal} disabled={Boolean(busyAction)}>
+              Close
+            </Button>
+          </div>
         </div>
+      </div>
 
-        {confirmAction ? (
+      {confirmAction ? (
+        <div
+          className="fixed inset-0 z-[60] flex items-center justify-center bg-stone-950/40 px-4"
+          onClick={() => setConfirmAction(null)}
+        >
           <div
-            className="absolute inset-0 flex items-center justify-center rounded-[28px] bg-stone-950/30 px-4"
-            onClick={() => setConfirmAction(null)}
+            className="max-h-[90vh] w-full max-w-lg overflow-y-auto rounded-[24px] border border-stone-900/8 bg-white p-5 shadow-[0_18px_48px_rgba(24,24,24,0.18)]"
+            onClick={(event) => event.stopPropagation()}
           >
-            <div
-              className="w-full max-w-lg rounded-[24px] border border-stone-900/8 bg-white p-5 shadow-[0_18px_48px_rgba(24,24,24,0.18)]"
-              onClick={(event) => event.stopPropagation()}
-            >
-              <p className="text-[12px] font-semibold uppercase tracking-[0.18em] text-stone-500">
-                Confirmation
-              </p>
-              <h3 className="mt-2 text-xl font-semibold text-stone-950">
-                Confirm refund
-              </h3>
-              <p className="mt-2 text-sm leading-6 text-stone-500">
-                {confirmAction.label}. This action will reverse the selected ticket records.
-              </p>
-              {requireOverrideCode ? (
-                <label className="mt-5 block space-y-2">
-                  <span className="text-xs font-semibold uppercase tracking-[0.16em] text-stone-500">
-                    Admin override code
-                  </span>
-                  <Input
-                    type="password"
-                    value={adminOverrideCode}
-                    onChange={(event) => onCodeChange(event.target.value)}
-                    placeholder="Enter override code"
-                    disabled={Boolean(busyAction)}
-                  />
-                </label>
-              ) : null}
-              <div className="mt-5 flex justify-end gap-3">
-                <Button
-                  variant="outline"
-                  onClick={() => setConfirmAction(null)}
-                  disabled={Boolean(busyAction)}
+            <p className="text-[12px] font-semibold uppercase tracking-[0.18em] text-stone-500">
+              Confirmation
+            </p>
+            <h3 className="mt-2 text-xl font-semibold text-stone-950">
+              Confirm refund
+            </h3>
+            <p className="mt-2 text-sm leading-6 text-stone-500">
+              {confirmAction.label}. This action will reverse the selected ticket records.
+            </p>
+            {confirmAction.requiresCsoChoice ? (
+              <div className="mt-5 space-y-3">
+                <p className="text-xs font-semibold uppercase tracking-[0.16em] text-stone-500">
+                  Approved spill-over handling
+                </p>
+                <button
+                  type="button"
+                  className={`flex w-full items-center justify-between rounded-[20px] border px-4 py-4 text-left transition ${
+                    csoRefundMode === "return_to_tcso"
+                      ? "border-stone-950 bg-stone-100"
+                      : "border-stone-900/8 bg-stone-50 hover:border-stone-900/20"
+                  }`}
+                  onClick={() => setCsoRefundMode("return_to_tcso")}
                 >
-                  Cancel
-                </Button>
-                <Button
-                  onClick={handleConfirmRefund}
-                  disabled={Boolean(busyAction) || (requireOverrideCode && !adminOverrideCode.trim())}
+                  <div>
+                    <p className="font-semibold text-stone-950">Change back to TCSO</p>
+                    <p className="mt-1 text-sm text-stone-500">
+                      Keep the transaction amount unchanged and move approved spill-over back to pending.
+                    </p>
+                  </div>
+                </button>
+                <button
+                  type="button"
+                  className={`flex w-full items-center justify-between rounded-[20px] border px-4 py-4 text-left transition ${
+                    csoRefundMode === "refund_spill_over"
+                      ? "border-stone-950 bg-stone-100"
+                      : "border-stone-900/8 bg-stone-50 hover:border-stone-900/20"
+                  }`}
+                  onClick={() => setCsoRefundMode("refund_spill_over")}
                 >
-                  Confirm refund
-                </Button>
+                  <div>
+                    <p className="font-semibold text-stone-950">Refund spill-over</p>
+                    <p className="mt-1 text-sm text-stone-500">
+                      Move approved spill-over into overkill and reduce the active transaction amount.
+                    </p>
+                  </div>
+                </button>
               </div>
+            ) : null}
+            {requireOverrideCode ? (
+              <label className="mt-5 block space-y-2">
+                <span className="text-xs font-semibold uppercase tracking-[0.16em] text-stone-500">
+                  Admin override code
+                </span>
+                <Input
+                  type="password"
+                  value={adminOverrideCode}
+                  onChange={(event) => onCodeChange(event.target.value)}
+                  placeholder="Enter override code"
+                  disabled={Boolean(busyAction)}
+                />
+              </label>
+            ) : null}
+            <div className="mt-5 flex justify-end gap-3">
+              <Button
+                variant="outline"
+                onClick={() => setConfirmAction(null)}
+                disabled={Boolean(busyAction)}
+              >
+                Cancel
+              </Button>
+              <Button
+                onClick={handleConfirmRefund}
+                disabled={
+                  Boolean(busyAction) ||
+                  (confirmAction.requiresCsoChoice && !csoRefundMode) ||
+                  (requireOverrideCode && !adminOverrideCode.trim())
+                }
+              >
+                Confirm refund
+              </Button>
             </div>
           </div>
-        ) : null}
-      </div>
-    </div>
+        </div>
+      ) : null}
+    </>
   );
 }
diff --git a/flowbit-frontend/src/lib/overflow-client.ts b/flowbit-frontend/src/lib/overflow-client.ts
index fa1dac6..1b5eb55 100644
--- a/flowbit-frontend/src/lib/overflow-client.ts
+++ b/flowbit-frontend/src/lib/overflow-client.ts
@@ -233,6 +233,7 @@ export async function resolveOverflowAction(payload: {
   overflowId: number;
   action: "refund_overflow_only" | "refund_transaction" | "refund_ticket";
   adminOverrideCode?: string;
+  csoRefundMode?: "return_to_tcso" | "refund_spill_over";
   syncRepeatTicket?: boolean;
 }) {
   return apiRequest<{ message: string }>(`/overflows/${payload.overflowId}/resolve/`, {
@@ -240,6 +241,7 @@ export async function resolveOverflowAction(payload: {
     headers: authHeaders(),
     body: JSON.stringify({
       action: payload.action,
+      ...(payload.csoRefundMode ? { cso_refund_mode: payload.csoRefundMode } : {}),
       ...(payload.syncRepeatTicket ? { sync_repeat_ticket: true } : {}),
       ...(payload.adminOverrideCode
         ? { admin_override_code: payload.adminOverrideCode }
diff --git a/flowbit-frontend/src/lib/ticket-client.ts b/flowbit-frontend/src/lib/ticket-client.ts
index 2fa2c67..a1372e7 100644
--- a/flowbit-frontend/src/lib/ticket-client.ts
+++ b/flowbit-frontend/src/lib/ticket-client.ts
@@ -165,6 +165,7 @@ export async function resolveOverflowAction(payload: {
   overflowId: number;
   action: "refund_overflow_only" | "refund_transaction" | "refund_ticket";
   adminOverrideCode?: string;
+  csoRefundMode?: "return_to_tcso" | "refund_spill_over";
   syncRepeatTicket?: boolean;
 }) {
   return apiRequest<{ message: string }>(`/overflows/${payload.overflowId}/resolve/`, {
@@ -172,6 +173,7 @@ export async function resolveOverflowAction(payload: {
     headers: authHeaders(),
     body: JSON.stringify({
       action: payload.action,
+      ...(payload.csoRefundMode ? { cso_refund_mode: payload.csoRefundMode } : {}),
       ...(payload.syncRepeatTicket ? { sync_repeat_ticket: true } : {}),
       ...(payload.adminOverrideCode
         ? { admin_override_code: payload.adminOverrideCode }
@@ -185,6 +187,7 @@ export async function resolveTicketRefundAction(payload: {
   action: "refund_ticket" | "refund_transaction";
   transactionId?: number;
   adminOverrideCode?: string;
+  csoRefundMode?: "return_to_tcso" | "refund_spill_over";
   syncRepeatTicket?: boolean;
 }) {
   return apiRequest<{ message: string }>(`/tickets/${payload.ticketNumber}/refund/`, {
@@ -193,6 +196,7 @@ export async function resolveTicketRefundAction(payload: {
     body: JSON.stringify({
       action: payload.action,
       ...(payload.transactionId ? { transaction_id: payload.transactionId } : {}),
+      ...(payload.csoRefundMode ? { cso_refund_mode: payload.csoRefundMode } : {}),
       ...(payload.syncRepeatTicket ? { sync_repeat_ticket: true } : {}),
       ...(payload.adminOverrideCode
         ? { admin_override_code: payload.adminOverrideCode }