diff --git a/services/github/pulls/get_open_pull_requests.py b/services/github/pulls/get_open_pull_requests.py
index 2eba477b..72607b32 100644
--- a/services/github/pulls/get_open_pull_requests.py
+++ b/services/github/pulls/get_open_pull_requests.py
@@ -5,7 +5,7 @@
 
 
 @handle_exceptions(default_return_value=[], raise_on_error=False)
-def get_open_pull_requests(owner: str, repo: str, target_branch: str, token: str):
+def get_open_pull_requests(owner: str, repo: str, token: str):
     """https://docs.github.com/en/rest/pulls/pulls?apiVersion=2022-11-28#list-pull-requests"""
     url = f"{GITHUB_API_URL}/repos/{owner}/{repo}/pulls"
     headers = create_headers(token=token)
@@ -13,8 +13,7 @@ def get_open_pull_requests(owner: str, repo: str, target_branch: str, token: str
     page = 1
 
     while True:
-        params = {
-            "base": target_branch,
+        params: dict[str, str | int] = {
             "state": "open",
             "per_page": PER_PAGE,
             "page": page,
diff --git a/services/github/pulls/test_get_open_pull_requests.py b/services/github/pulls/test_get_open_pull_requests.py
index 5e212d96..a0507a63 100644
--- a/services/github/pulls/test_get_open_pull_requests.py
+++ b/services/github/pulls/test_get_open_pull_requests.py
@@ -35,7 +35,6 @@ def test_get_open_pull_requests_success():
         result = get_open_pull_requests(
             owner="test-owner",
             repo="test-repo",
-            target_branch="main",
             token="test-token",
         )
 
@@ -75,7 +74,6 @@ def test_get_open_pull_requests_pagination():
         result = get_open_pull_requests(
             owner="test-owner",
             repo="test-repo",
-            target_branch="develop",
             token="test-token",
         )
 
@@ -92,7 +90,6 @@ def test_get_open_pull_requests_empty():
         result = get_open_pull_requests(
             owner="test-owner",
             repo="test-repo",
-            target_branch="main",
             token="test-token",
         )
 
@@ -104,7 +101,6 @@ def test_get_open_pull_requests_error():
         result = get_open_pull_requests(
             owner="test-owner",
             repo="test-repo",
-            target_branch="main",
             token="test-token",
         )
 
@@ -151,7 +147,6 @@ def test_get_open_pull_requests_filters_non_gitauto_prs():
         result = get_open_pull_requests(
             owner="test-owner",
             repo="test-repo",
-            target_branch="main",
             token="test-token",
         )
 
@@ -193,7 +188,6 @@ def test_get_open_pull_requests_no_gitauto_prs():
         result = get_open_pull_requests(
             owner="test-owner",
             repo="test-repo",
-            target_branch="main",
             token="test-token",
         )
 
diff --git a/services/webhook/push_handler.py b/services/webhook/push_handler.py
index 6dfa3960..6f873224 100644
--- a/services/webhook/push_handler.py
+++ b/services/webhook/push_handler.py
@@ -39,9 +39,7 @@ def handle_push(payload: PushWebhookPayload):
 
     token = get_installation_access_token(installation_id=installation_id)
 
-    open_prs = get_open_pull_requests(
-        owner=owner_name, repo=repo_name, target_branch=target_branch, token=token
-    )
+    open_prs = get_open_pull_requests(owner=owner_name, repo=repo_name, token=token)
 
     if not open_prs:
         # No GitAuto PRs targeting this branch
diff --git a/services/webhook/schedule_handler.py b/services/webhook/schedule_handler.py
index 893f2236..49ca950f 100644
--- a/services/webhook/schedule_handler.py
+++ b/services/webhook/schedule_handler.py
@@ -185,9 +185,7 @@ def schedule_handler(event: EventBridgeSchedulerEvent):
     )
 
     # Get open PRs once before the loop
-    open_prs = get_open_pull_requests(
-        owner=owner_name, repo=repo_name, target_branch=target_branch, token=token
-    )
+    open_prs = get_open_pull_requests(owner=owner_name, repo=repo_name, token=token)
 
     # Find the first suitable file from sorted list
     target_item = None
@@ -284,8 +282,16 @@ def schedule_handler(event: EventBridgeSchedulerEvent):
             continue
 
         # Skip files that have open PRs (temporary, don't exclude)
-        if any(item_path in pr.get("title", "") for pr in open_prs):
-            logger.info("Skipping %s: has open PR", item_path)
+        matching_pr = next(
+            (pr for pr in open_prs if item_path in pr.get("title", "")), None
+        )
+        if matching_pr:
+            logger.info(
+                "Skipping %s: has open PR #%s (%s)",
+                item_path,
+                matching_pr.get("number"),
+                matching_pr.get("base", {}).get("ref"),
+            )
             continue
 
         # Final check: Use Claude AI to determine if this file should be tested (expensive, so run last)
diff --git a/services/webhook/test_push_handler.py b/services/webhook/test_push_handler.py
index 4b090a6d..593492d6 100644
--- a/services/webhook/test_push_handler.py
+++ b/services/webhook/test_push_handler.py
@@ -170,7 +170,7 @@ def test_handle_push_no_open_prs_returns_early(
     mock_get_repository.assert_called_once_with(owner_id=123, repo_id=456)
     mock_get_token.assert_called_once_with(installation_id=789)
     mock_get_open_prs.assert_called_once_with(
-        owner="test-owner", repo="test-repo", target_branch="main", token="test-token"
+        owner="test-owner", repo="test-repo", token="test-token"
     )
     mock_update_pr.assert_not_called()
     mock_logger.info.assert_not_called()
@@ -212,7 +212,7 @@ def test_handle_push_local_main_to_remote_main_handled(
     mock_get_repository.assert_called_once_with(owner_id=123, repo_id=456)
     mock_get_token.assert_called_once_with(installation_id=789)
     mock_get_open_prs.assert_called_once_with(
-        owner="test-owner", repo="test-repo", target_branch="main", token="test-token"
+        owner="test-owner", repo="test-repo", token="test-token"
     )
     assert mock_update_pr.call_count == 2
     mock_update_pr.assert_any_call(
@@ -257,7 +257,7 @@ def test_handle_push_remote_feature_to_remote_main_handled(
     mock_get_repository.assert_called_once_with(owner_id=123, repo_id=456)
     mock_get_token.assert_called_once_with(installation_id=789)
     mock_get_open_prs.assert_called_once_with(
-        owner="test-owner", repo="test-repo", target_branch="main", token="test-token"
+        owner="test-owner", repo="test-repo", token="test-token"
     )
     mock_update_pr.assert_called_once_with(
         owner="test-owner", repo="test-repo", pr_number=5, token="test-token"
@@ -390,7 +390,7 @@ def test_handle_push_no_gitauto_prs_returns_early(
     mock_get_repository.assert_called_once_with(owner_id=123, repo_id=456)
     mock_get_token.assert_called_once_with(installation_id=789)
     mock_get_open_prs.assert_called_once_with(
-        owner="test-owner", repo="test-repo", target_branch="main", token="test-token"
+        owner="test-owner", repo="test-repo", token="test-token"
     )
     mock_update_pr.assert_not_called()
     mock_logger.info.assert_not_called()
diff --git a/services/webhook/test_schedule_handler.py b/services/webhook/test_schedule_handler.py
index 9139a847..17f21950 100644
--- a/services/webhook/test_schedule_handler.py
+++ b/services/webhook/test_schedule_handler.py
@@ -464,6 +464,180 @@ def test_schedule_handler_prioritizes_zero_coverage_files(
         assert "updated_at" not in coverage_record
 
 
+@patch("services.webhook.schedule_handler.get_open_pull_requests")
+@patch("services.webhook.schedule_handler.should_skip_test")
+@patch("services.webhook.schedule_handler.is_schedule_paused")
+@patch("services.webhook.schedule_handler.get_installation_access_token")
+@patch("services.webhook.schedule_handler.get_repository")
+@patch("services.webhook.schedule_handler.check_availability")
+@patch("services.webhook.schedule_handler.get_default_branch")
+@patch("services.webhook.schedule_handler.get_file_tree")
+@patch("services.webhook.schedule_handler.get_all_coverages")
+@patch("services.webhook.schedule_handler.get_raw_content")
+def test_schedule_handler_skips_file_with_open_pr_on_different_branch(
+    mock_get_raw_content,
+    mock_get_all_coverages,
+    mock_get_file_tree,
+    mock_get_default_branch,
+    mock_check_availability,
+    mock_get_repository,
+    mock_get_token,
+    mock_is_paused,
+    mock_should_skip_test,
+    mock_get_open_pull_requests,
+    mock_event,
+):
+    mock_get_token.return_value = "test-token"
+    mock_is_paused.return_value = False
+    mock_get_repository.return_value = {
+        "trigger_on_schedule": True,
+        "target_branch": "master",
+    }
+    mock_check_availability.return_value = {
+        "can_proceed": True,
+        "billing_type": "exception",
+        "requests_left": None,
+        "credit_balance_usd": 0,
+        "period_end_date": None,
+        "user_message": "",
+        "log_message": "Exception owner - unlimited access.",
+    }
+    mock_get_default_branch.return_value = ("master", None)
+    mock_get_file_tree.return_value = [
+        {"path": "src/app.php", "type": "blob", "size": 100},
+    ]
+    mock_get_all_coverages.return_value = [
+        {
+            "id": 1,
+            "full_path": "src/app.php",
+            "owner_id": 123,
+            "repo_id": 456,
+            "branch_name": "master",
+            "created_by": "test-user",
+            "updated_by": "test-user",
+            "level": "file",
+            "file_size": 100,
+            "statement_coverage": 10.0,
+            "function_coverage": 50.0,
+            "branch_coverage": 100.0,
+            "line_coverage": 10.0,
+            "package_name": None,
+            "language": "php",
+            "uncovered_lines": None,
+            "uncovered_functions": None,
+            "uncovered_branches": None,
+            "created_at": "2024-01-01",
+            "updated_at": "2024-01-01",
+            "github_issue_url": None,
+            "is_excluded_from_testing": False,
+        },
+    ]
+    mock_get_raw_content.return_value = "<?php function test() { return 1; }"
+    mock_should_skip_test.return_value = False
+    # Open PR targeting a DIFFERENT branch but for the same file
+    mock_get_open_pull_requests.return_value = [
+        {
+            "number": 100,
+            "title": "Schedule: Add unit tests to src/app.php",
+            "base": {"ref": "release/20260311"},
+            "user": {"login": "gitauto-ai[bot]"},
+        },
+    ]
+
+    result = schedule_handler(mock_event)
+
+    assert result["status"] == "skipped"
+    assert "No suitable file found" in result["message"]
+
+
+@patch("services.webhook.schedule_handler.get_open_pull_requests")
+@patch("services.webhook.schedule_handler.should_skip_test")
+@patch("services.webhook.schedule_handler.is_schedule_paused")
+@patch("services.webhook.schedule_handler.get_installation_access_token")
+@patch("services.webhook.schedule_handler.get_repository")
+@patch("services.webhook.schedule_handler.check_availability")
+@patch("services.webhook.schedule_handler.get_default_branch")
+@patch("services.webhook.schedule_handler.get_file_tree")
+@patch("services.webhook.schedule_handler.get_all_coverages")
+@patch("services.webhook.schedule_handler.get_raw_content")
+def test_schedule_handler_skips_file_with_open_pr_different_title_format(
+    mock_get_raw_content,
+    mock_get_all_coverages,
+    mock_get_file_tree,
+    mock_get_default_branch,
+    mock_check_availability,
+    mock_get_repository,
+    mock_get_token,
+    mock_is_paused,
+    mock_should_skip_test,
+    mock_get_open_pull_requests,
+    mock_event,
+):
+    """Dedup works even when the existing PR uses an old title format, because the
+    check is a file-path substring match, not an exact title match."""
+    mock_get_token.return_value = "test-token"
+    mock_is_paused.return_value = False
+    mock_get_repository.return_value = {
+        "trigger_on_schedule": True,
+        "target_branch": "master",
+    }
+    mock_check_availability.return_value = {
+        "can_proceed": True,
+        "billing_type": "exception",
+        "requests_left": None,
+        "credit_balance_usd": 0,
+        "period_end_date": None,
+        "user_message": "",
+        "log_message": "Exception owner - unlimited access.",
+    }
+    mock_get_default_branch.return_value = ("master", None)
+    mock_get_file_tree.return_value = [
+        {"path": "src/app.php", "type": "blob", "size": 100},
+    ]
+    mock_get_all_coverages.return_value = [
+        {
+            "id": 1,
+            "full_path": "src/app.php",
+            "owner_id": 123,
+            "repo_id": 456,
+            "branch_name": "master",
+            "created_by": "test-user",
+            "updated_by": "test-user",
+            "level": "file",
+            "file_size": 100,
+            "statement_coverage": 10.0,
+            "function_coverage": 50.0,
+            "branch_coverage": 100.0,
+            "line_coverage": 10.0,
+            "package_name": None,
+            "language": "php",
+            "uncovered_lines": None,
+            "uncovered_functions": None,
+            "uncovered_branches": None,
+            "created_at": "2024-01-01",
+            "updated_at": "2024-01-01",
+            "github_issue_url": None,
+            "is_excluded_from_testing": False,
+        },
+    ]
+    mock_get_raw_content.return_value = "<?php function test() { return 1; }"
+    mock_should_skip_test.return_value = False
+    # Old title format ("for uncovered code in") differs from current ("to"/"Achieve 100%")
+    mock_get_open_pull_requests.return_value = [
+        {
+            "number": 100,
+            "title": "Schedule: Add unit tests for uncovered code in src/app.php",
+            "base": {"ref": "release/20260311"},
+            "user": {"login": "gitauto-ai[bot]"},
+        },
+    ]
+
+    result = schedule_handler(mock_event)
+
+    assert result["status"] == "skipped"
+    assert "No suitable file found" in result["message"]
+
+
 @patch("services.webhook.schedule_handler.get_open_pull_requests")
 @patch("services.webhook.schedule_handler.evaluate_condition")
 @patch("services.webhook.schedule_handler.should_skip_test")