diff --git a/api/app/utils/utils.py b/api/app/utils/utils.py
index 74ccdad0..b19092c9 100644
--- a/api/app/utils/utils.py
+++ b/api/app/utils/utils.py
@@ -17,8 +17,11 @@
 from urllib.parse import parse_qs, quote, urlencode, urlparse, urlunparse
 
 from app import EPSG, HOSTNAME, TOP_VALUE
+from asyncpg.exceptions import UniqueViolationError
 from asyncpg.types import Range
 from dateutil import parser
+from fastapi import status
+from fastapi.responses import JSONResponse
 
 _USERNAME_RE = re.compile(r"^[a-zA-Z0-9_]{3,63}$")
 
@@ -269,6 +272,29 @@ def validate_required_keys(payload, required_keys):
         raise Exception(f"Missing required fields: {', '.join(missing)}")
 
 
+def handle_duplicate_error(e=None):
+    message = "Entity already exists."
+    
+    if e and hasattr(e, "detail") and e.detail:
+        # Example detail: "Key (name)=(duplicate test) already exists."
+        # We can extract the column name and the value from here
+        import re
+        match = re.search(r"Key \((.*?)\)=\((.*?)\) already exists", e.detail)
+        if match:
+            column = match.group(1)
+            value = match.group(2)
+            message = f"An entity with {column} '{value}' already exists."
+
+    return JSONResponse(
+        status_code=status.HTTP_409_CONFLICT,
+        content={
+            "code": 409,
+            "type": "error",
+            "message": message,
+        },
+    )
+
+
 def validate_epsg(key):
     crs = key.get("crs")
     if crs is not None:
diff --git a/api/app/v1/endpoints/create/feature_of_interest.py b/api/app/v1/endpoints/create/feature_of_interest.py
index a70fa5e0..287408a9 100644
--- a/api/app/v1/endpoints/create/feature_of_interest.py
+++ b/api/app/v1/endpoints/create/feature_of_interest.py
@@ -14,9 +14,13 @@
 
 from app import AUTHORIZATION, POSTGRES_PORT_WRITE, VERSIONING
 from app.db.asyncpg_db import get_pool, get_pool_w
-from app.utils.utils import validate_payload_keys, validate_required_keys
+from app.utils.utils import (
+    handle_duplicate_error,
+    validate_payload_keys,
+    validate_required_keys,
+)
 from app.v1.endpoints.functions import set_role
-from asyncpg.exceptions import InsufficientPrivilegeError
+from asyncpg.exceptions import InsufficientPrivilegeError, UniqueViolationError
 from fastapi import APIRouter, Body, Depends, Header, Request, status
 from fastapi.responses import JSONResponse, Response
 
@@ -100,6 +104,8 @@ async def create_feature_of_interest(
             status_code=status.HTTP_201_CREATED,
             headers={"location": header},
         )
+    except UniqueViolationError as e:
+        return handle_duplicate_error(e)
     except InsufficientPrivilegeError:
         return JSONResponse(
             status_code=status.HTTP_401_UNAUTHORIZED,
diff --git a/api/app/v1/endpoints/create/location.py b/api/app/v1/endpoints/create/location.py
index a21786da..99cfdbdd 100644
--- a/api/app/v1/endpoints/create/location.py
+++ b/api/app/v1/endpoints/create/location.py
@@ -14,9 +14,13 @@
 
 from app import AUTHORIZATION, POSTGRES_PORT_WRITE, VERSIONING
 from app.db.asyncpg_db import get_pool, get_pool_w
-from app.utils.utils import validate_payload_keys, validate_required_keys
+from app.utils.utils import (
+    handle_duplicate_error,
+    validate_payload_keys,
+    validate_required_keys,
+)
 from app.v1.endpoints.functions import set_role
-from asyncpg.exceptions import InsufficientPrivilegeError
+from asyncpg.exceptions import InsufficientPrivilegeError, UniqueViolationError
 from fastapi import APIRouter, Body, Depends, Header, Request, status
 from fastapi.responses import JSONResponse, Response
 
@@ -81,6 +85,7 @@ async def create_location(
 
         async with pool.acquire() as connection:
             async with connection.transaction():
+            
                 if current_user is not None:
                     await set_role(connection, current_user)
 
@@ -100,6 +105,8 @@ async def create_location(
             status_code=status.HTTP_201_CREATED,
             headers={"location": header},
         )
+    except UniqueViolationError as e:
+        return handle_duplicate_error(e)
     except InsufficientPrivilegeError:
         return JSONResponse(
             status_code=status.HTTP_401_UNAUTHORIZED,
@@ -115,7 +122,7 @@ async def create_location(
             content={
                 "code": 400,
                 "type": "error",
-                "message": str(e),
+                "message": f"[{type(e).__name__}] {str(e)}"
             },
         )
 
@@ -172,6 +179,8 @@ async def create_location_for_thing(
             status_code=status.HTTP_201_CREATED,
             headers={"location": header},
         )
+    except UniqueViolationError as e:
+        return handle_duplicate_error(e)
     except InsufficientPrivilegeError:
         return JSONResponse(
             status_code=status.HTTP_401_UNAUTHORIZED,
@@ -187,6 +196,6 @@ async def create_location_for_thing(
             content={
                 "code": 400,
                 "type": "error",
-                "message": str(e),
+                "message": f"[{type(e).__name__}] {str(e)}",
             },
         )
diff --git a/api/app/v1/endpoints/create/network.py b/api/app/v1/endpoints/create/network.py
index 48c5abac..88862902 100644
--- a/api/app/v1/endpoints/create/network.py
+++ b/api/app/v1/endpoints/create/network.py
@@ -13,9 +13,13 @@
 # limitations under the License.
 from app import AUTHORIZATION, POSTGRES_PORT_WRITE, VERSIONING
 from app.db.asyncpg_db import get_pool, get_pool_w
-from app.utils.utils import validate_payload_keys, validate_required_keys
+from app.utils.utils import (
+    handle_duplicate_error,
+    validate_payload_keys,
+    validate_required_keys,
+)
 from app.v1.endpoints.functions import set_role
-from asyncpg.exceptions import InsufficientPrivilegeError
+from asyncpg.exceptions import InsufficientPrivilegeError, UniqueViolationError
 from fastapi import APIRouter, Body, Depends, Header, Request, status
 from fastapi.responses import JSONResponse, Response
 
@@ -90,6 +94,8 @@ async def create_network(
             status_code=status.HTTP_201_CREATED,
             headers={"location": header},
         )
+    except UniqueViolationError as e:
+        return handle_duplicate_error(e)
     except InsufficientPrivilegeError as e:
         return JSONResponse(
             status_code=status.HTTP_401_UNAUTHORIZED,
diff --git a/api/app/v1/endpoints/create/observed_property.py b/api/app/v1/endpoints/create/observed_property.py
index 1a4cbd9b..abd53e6a 100644
--- a/api/app/v1/endpoints/create/observed_property.py
+++ b/api/app/v1/endpoints/create/observed_property.py
@@ -14,9 +14,13 @@
 
 from app import AUTHORIZATION, POSTGRES_PORT_WRITE, VERSIONING
 from app.db.asyncpg_db import get_pool, get_pool_w
-from app.utils.utils import validate_payload_keys, validate_required_keys
+from app.utils.utils import (
+    handle_duplicate_error,
+    validate_payload_keys,
+    validate_required_keys,
+)
 from app.v1.endpoints.functions import set_role
-from asyncpg.exceptions import InsufficientPrivilegeError
+from asyncpg.exceptions import InsufficientPrivilegeError, UniqueViolationError
 from fastapi import APIRouter, Body, Depends, Header, Request, status
 from fastapi.responses import JSONResponse, Response
 
@@ -98,6 +102,8 @@ async def create_observed_property(
             status_code=status.HTTP_201_CREATED,
             headers={"location": header},
         )
+    except UniqueViolationError as e:
+        return handle_duplicate_error(e)
     except InsufficientPrivilegeError:
         return JSONResponse(
             status_code=status.HTTP_401_UNAUTHORIZED,
diff --git a/api/app/v1/endpoints/create/sensor.py b/api/app/v1/endpoints/create/sensor.py
index 5f6c3f3d..445e8c85 100644
--- a/api/app/v1/endpoints/create/sensor.py
+++ b/api/app/v1/endpoints/create/sensor.py
@@ -14,9 +14,13 @@
 
 from app import AUTHORIZATION, POSTGRES_PORT_WRITE, VERSIONING
 from app.db.asyncpg_db import get_pool, get_pool_w
-from app.utils.utils import validate_payload_keys, validate_required_keys
+from app.utils.utils import (
+    handle_duplicate_error,
+    validate_payload_keys,
+    validate_required_keys,
+)
 from app.v1.endpoints.functions import set_role
-from asyncpg.exceptions import InsufficientPrivilegeError
+from asyncpg.exceptions import InsufficientPrivilegeError, UniqueViolationError
 from fastapi import APIRouter, Body, Depends, Header, Request, status
 from fastapi.responses import JSONResponse, Response
 
@@ -100,6 +104,8 @@ async def create_sensor(
             status_code=status.HTTP_201_CREATED,
             headers={"location": header},
         )
+    except UniqueViolationError as e:
+        return handle_duplicate_error(e)
     except InsufficientPrivilegeError:
         return JSONResponse(
             status_code=status.HTTP_401_UNAUTHORIZED,
diff --git a/api/app/v1/endpoints/create/thing.py b/api/app/v1/endpoints/create/thing.py
index 1591d7a7..f8562d76 100644
--- a/api/app/v1/endpoints/create/thing.py
+++ b/api/app/v1/endpoints/create/thing.py
@@ -14,9 +14,13 @@
 
 from app import AUTHORIZATION, POSTGRES_PORT_WRITE, VERSIONING
 from app.db.asyncpg_db import get_pool, get_pool_w
-from app.utils.utils import validate_payload_keys, validate_required_keys
+from app.utils.utils import (
+    handle_duplicate_error,
+    validate_payload_keys,
+    validate_required_keys,
+)
 from app.v1.endpoints.functions import set_role
-from asyncpg.exceptions import InsufficientPrivilegeError
+from asyncpg.exceptions import InsufficientPrivilegeError, UniqueViolationError
 from fastapi import APIRouter, Body, Depends, Header, Request, status
 from fastapi.responses import JSONResponse, Response
 
@@ -98,6 +102,8 @@ async def create_thing(
             status_code=status.HTTP_201_CREATED,
             headers={"location": header},
         )
+    except UniqueViolationError as e:
+        return handle_duplicate_error(e)
     except InsufficientPrivilegeError as e:
         return JSONResponse(
             status_code=status.HTTP_401_UNAUTHORIZED,
@@ -171,6 +177,8 @@ async def create_thing_for_location(
             status_code=status.HTTP_201_CREATED,
             headers={"location": header},
         )
+    except UniqueViolationError as e:
+        return handle_duplicate_error(e)
     except InsufficientPrivilegeError:
         return JSONResponse(
             status_code=status.HTTP_401_UNAUTHORIZED,
diff --git a/api/app/v1/endpoints/update/feature_of_interest.py b/api/app/v1/endpoints/update/feature_of_interest.py
index d1a22e2b..5d5f855b 100644
--- a/api/app/v1/endpoints/update/feature_of_interest.py
+++ b/api/app/v1/endpoints/update/feature_of_interest.py
@@ -14,13 +14,13 @@
 
 from app import AUTHORIZATION, POSTGRES_PORT_WRITE, VERSIONING
 from app.db.asyncpg_db import get_pool, get_pool_w
-from app.utils.utils import validate_payload_keys
+from app.utils.utils import handle_duplicate_error, validate_payload_keys
 from app.v1.endpoints.functions import (
     get_datastreams_from_foi,
     set_role,
     update_datastream_observedArea,
 )
-from asyncpg.exceptions import InsufficientPrivilegeError
+from asyncpg.exceptions import InsufficientPrivilegeError, UniqueViolationError
 from fastapi import APIRouter, Body, Depends, Header, status
 from fastapi.responses import JSONResponse, Response
 
@@ -133,6 +133,8 @@ async def update_feature_of_interest(
                     await connection.execute("RESET ROLE;")
 
         return Response(status_code=status.HTTP_200_OK)
+    except UniqueViolationError as e:
+        return handle_duplicate_error(e)
     except InsufficientPrivilegeError:
         return JSONResponse(
             status_code=status.HTTP_401_UNAUTHORIZED,
diff --git a/api/app/v1/endpoints/update/location.py b/api/app/v1/endpoints/update/location.py
index 36ba4bee..7679d359 100644
--- a/api/app/v1/endpoints/update/location.py
+++ b/api/app/v1/endpoints/update/location.py
@@ -14,9 +14,9 @@
 
 from app import AUTHORIZATION, POSTGRES_PORT_WRITE, VERSIONING
 from app.db.asyncpg_db import get_pool, get_pool_w
-from app.utils.utils import validate_payload_keys
+from app.utils.utils import handle_duplicate_error, validate_payload_keys
 from app.v1.endpoints.functions import set_role
-from asyncpg.exceptions import InsufficientPrivilegeError
+from asyncpg.exceptions import InsufficientPrivilegeError, UniqueViolationError
 from fastapi import APIRouter, Body, Depends, Header, status
 from fastapi.responses import JSONResponse, Response
 
@@ -115,6 +115,8 @@ async def update_location(
                     await connection.execute("RESET ROLE;")
 
         return Response(status_code=status.HTTP_200_OK)
+    except UniqueViolationError as e:
+        return handle_duplicate_error(e)
     except InsufficientPrivilegeError:
         return JSONResponse(
             status_code=status.HTTP_401_UNAUTHORIZED,
diff --git a/api/app/v1/endpoints/update/network.py b/api/app/v1/endpoints/update/network.py
index a3761668..15565f0b 100644
--- a/api/app/v1/endpoints/update/network.py
+++ b/api/app/v1/endpoints/update/network.py
@@ -13,9 +13,9 @@
 # limitations under the License.
 from app import AUTHORIZATION, POSTGRES_PORT_WRITE, VERSIONING
 from app.db.asyncpg_db import get_pool, get_pool_w
-from app.utils.utils import validate_payload_keys
+from app.utils.utils import handle_duplicate_error, validate_payload_keys
 from app.v1.endpoints.functions import set_role
-from asyncpg.exceptions import InsufficientPrivilegeError
+from asyncpg.exceptions import InsufficientPrivilegeError, UniqueViolationError
 from fastapi import APIRouter, Body, Depends, Header, status
 from fastapi.responses import JSONResponse, Response
 
@@ -101,6 +101,8 @@ async def update_network(
                     await connection.execute("RESET ROLE;")
 
         return Response(status_code=status.HTTP_200_OK)
+    except UniqueViolationError as e:
+        return handle_duplicate_error(e)
     except InsufficientPrivilegeError:
         return JSONResponse(
             status_code=status.HTTP_401_UNAUTHORIZED,
diff --git a/api/app/v1/endpoints/update/observed_property.py b/api/app/v1/endpoints/update/observed_property.py
index a6b00ed0..3e02eef1 100644
--- a/api/app/v1/endpoints/update/observed_property.py
+++ b/api/app/v1/endpoints/update/observed_property.py
@@ -14,9 +14,9 @@
 
 from app import AUTHORIZATION, POSTGRES_PORT_WRITE, VERSIONING
 from app.db.asyncpg_db import get_pool, get_pool_w
-from app.utils.utils import validate_payload_keys
+from app.utils.utils import handle_duplicate_error, validate_payload_keys
 from app.v1.endpoints.functions import set_role
-from asyncpg.exceptions import InsufficientPrivilegeError
+from asyncpg.exceptions import InsufficientPrivilegeError, UniqueViolationError
 from fastapi import APIRouter, Body, Depends, Header, status
 from fastapi.responses import JSONResponse, Response
 
@@ -117,6 +117,8 @@ async def update_observed_property(
                     await connection.execute("RESET ROLE;")
 
         return Response(status_code=status.HTTP_200_OK)
+    except UniqueViolationError as e:
+        return handle_duplicate_error(e)
     except InsufficientPrivilegeError:
         return JSONResponse(
             status_code=status.HTTP_401_UNAUTHORIZED,
diff --git a/api/app/v1/endpoints/update/sensor.py b/api/app/v1/endpoints/update/sensor.py
index 662ef659..a9fba78b 100644
--- a/api/app/v1/endpoints/update/sensor.py
+++ b/api/app/v1/endpoints/update/sensor.py
@@ -14,9 +14,9 @@
 
 from app import AUTHORIZATION, POSTGRES_PORT_WRITE, VERSIONING
 from app.db.asyncpg_db import get_pool, get_pool_w
-from app.utils.utils import validate_payload_keys
+from app.utils.utils import handle_duplicate_error, validate_payload_keys
 from app.v1.endpoints.functions import set_role
-from asyncpg.exceptions import InsufficientPrivilegeError
+from asyncpg.exceptions import InsufficientPrivilegeError, UniqueViolationError
 from fastapi import APIRouter, Body, Depends, Header, status
 from fastapi.responses import JSONResponse, Response
 
@@ -110,6 +110,8 @@ async def update_sensor(
                     await connection.execute("RESET ROLE;")
 
         return Response(status_code=status.HTTP_200_OK)
+    except UniqueViolationError as e:
+        return handle_duplicate_error(e)
     except InsufficientPrivilegeError:
         return JSONResponse(
             status_code=status.HTTP_401_UNAUTHORIZED,
diff --git a/api/app/v1/endpoints/update/thing.py b/api/app/v1/endpoints/update/thing.py
index ac5a3b71..cbdc4944 100644
--- a/api/app/v1/endpoints/update/thing.py
+++ b/api/app/v1/endpoints/update/thing.py
@@ -14,9 +14,9 @@
 
 from app import AUTHORIZATION, POSTGRES_PORT_WRITE, VERSIONING
 from app.db.asyncpg_db import get_pool, get_pool_w
-from app.utils.utils import validate_payload_keys
+from app.utils.utils import handle_duplicate_error, validate_payload_keys
 from app.v1.endpoints.functions import set_role
-from asyncpg.exceptions import InsufficientPrivilegeError
+from asyncpg.exceptions import InsufficientPrivilegeError, UniqueViolationError
 from fastapi import APIRouter, Body, Depends, Header, status
 from fastapi.responses import JSONResponse, Response
 
@@ -107,6 +107,8 @@ async def update_thing(
                     await connection.execute("RESET ROLE;")
 
         return Response(status_code=status.HTTP_200_OK)
+    except UniqueViolationError as e:
+        return handle_duplicate_error(e)
     except InsufficientPrivilegeError:
         return JSONResponse(
             status_code=status.HTTP_401_UNAUTHORIZED,