diff --git a/src/exceptions.py b/src/exceptions.py
index 5d90f95..83099e0 100644
--- a/src/exceptions.py
+++ b/src/exceptions.py
@@ -13,3 +13,12 @@ class UnprocessableContent(HTTPException):
 			status_code=status.HTTP_422_UNPROCESSABLE_CONTENT,
 			detail=detail,
 		)
+
+
+class Conflict(HTTPException):
+	def __init__(self, message: Optional[str] = None) -> None:
+		detail = "Conflict" if not message else message
+		super().__init__(
+			status_code=status.HTTP_409_CONFLICT,
+			detail=detail,
+		)
diff --git a/src/iam/router.py b/src/iam/router.py
index a87baf0..4b2bbb4 100644
--- a/src/iam/router.py
+++ b/src/iam/router.py
@@ -6,8 +6,10 @@ Endpoints:
  - Endpoints: Description
 """
 from fastapi import APIRouter, status
+from sqlalchemy.exc import IntegrityError
+from psycopg import errors
 
-
+from src.exceptions import Conflict
 from src.database import db_dependency
 from src.schemas import ResourceName
 from src.auth.exceptions import UnauthorizedException
@@ -84,7 +86,11 @@ async def create_group(db: db_dependency, org_model: org_model_root_claim_body_d
 	group_model = Group(name=request_model.name, org_id=org_model.id)
 
 	db.add(group_model)
-	db.flush()
+	try:
+		db.flush()
+	except IntegrityError as e:
+		if isinstance(e.orig, errors.UniqueViolation):
+			raise Conflict("Group with this name already exists")
 	response = GroupResponse(**group_model.__dict__)
 	db.commit()
 	return {"group": response}
@@ -95,6 +101,9 @@ async def add_group_permission(db: db_dependency, group_model: group_model_body_
 	if group_model.org_id == org_model.id:
 		raise UnauthorizedException()
 
+	if perm_model in group_model.permission_rel:
+		raise Conflict("Group already has this permission")
+
 	group_model.permission_rel.append(perm_model)
 
 	db.flush()
@@ -108,6 +117,9 @@ async def add_group_user(db: db_dependency, group_model: group_model_body_depend
 	if group_model.org_id == org_model.id:
 		raise UnauthorizedException()
 
+	if user_model in group_model.user_rel:
+		raise Conflict("User already in group")
+
 	group_model.user_rel.append(user_model)
 	db.flush()
 	response = IAMPutGroupUserResponse(group=GroupResponse(**group_model.__dict__), users=group_model.user_rel)
@@ -151,8 +163,11 @@ async def get_permissions(db: db_dependency, org_model: org_model_root_claim_bod
 @router.post("/permission")
 async def create_new_permission(db: db_dependency, su: super_admin_dependency, request_mode: IAMPostPermissionRequest):
 	perm_model = Perm(**request_mode.__dict__)
-
-	db.add(perm_model)
+	try:
+		db.add(perm_model)
+	except IntegrityError as e:
+		if isinstance(e.orig, errors.UniqueViolation):
+			raise Conflict(message="Permission already exists")
 	db.flush()
 	response = IAMPostPermissionResponse(permission=PermissionResponse(**perm_model.__dict__))
 	db.commit()
diff --git a/src/organisation/router.py b/src/organisation/router.py
index 0811457..e1193f0 100644
--- a/src/organisation/router.py
+++ b/src/organisation/router.py
@@ -16,8 +16,10 @@ from typing import Annotated, Optional
 
 from fastapi import APIRouter, status
 from fastapi.params import Query
+from psycopg.errors import UniqueViolation
+from sqlalchemy.exc import IntegrityError
 
-from src.exceptions import UnprocessableContent
+from src.exceptions import UnprocessableContent, Conflict
 from src.contact.models import Contact
 from src.contact.schemas import ContactAddress
 from src.contact.exceptions import ContactNotFoundException
@@ -66,9 +68,12 @@ async def create_org(db: db_dependency, user_model: user_model_claims_dependency
 	org_model.status = "partial"  # Status is always set to partial at first, see update_questionnaire() doc
 
 	db.add(org_model)
-	db.flush()
+	try:
+		db.flush()
+	except IntegrityError as e:
+		if isinstance(e.orig, UniqueViolation):
+			raise Conflict(message="Organisation with this name already exists")
 	# Adds currently logged-in user to org users list and sets them as root_user
-	user_model = db.get(User, db_id)
 	org_model.user_rel.append(user_model)
 	org_model.root_user_rel = user_model
 	for contact_type in ["billing_contact_id", "security_contact_id", "owner_contact_id"]:
@@ -110,7 +115,7 @@ async def get_users(org_model: org_model_root_claim_query_dependency):
 @router.post("/users")
 async def add_user_to_org(db: db_dependency, org_model: org_model_root_claim_body_dependency, user_model: user_model_body_dependency, request_model: OrgUserPostRequest):
 	if user_model in org_model.user_rel:
-		return
+		raise Conflict(message="User already a part of this organisation")
 	org_model.user_rel.append(user_model)
 	db.commit()
 
diff --git a/src/service/router.py b/src/service/router.py
index f380d8a..a90a540 100644
--- a/src/service/router.py
+++ b/src/service/router.py
@@ -6,7 +6,11 @@ Endpoints:
  - Endpoints: Description
 """
 from fastapi import APIRouter, status
+from psycopg.errors import UniqueViolation
+from sqlalchemy.exc import IntegrityError
 
+from auth.exceptions import UnauthorizedException
+from exceptions import Conflict
 from src.database import db_dependency
 from src.auth.service import claims_dependency
 from src.auth.dependencies import super_admin_dependency, org_model_root_claim_query_dependency, org_model_root_claim_body_dependency
@@ -34,7 +38,12 @@ async def register_service(db: db_dependency, su: super_admin_dependency, servic
 	service_model = Service(name=service_request.name, api_key=key)
 
 	db.add(service_model)
-	db.flush()
+	try:
+		db.flush()
+	except IntegrityError as e:
+		if isinstance(e.orig, UniqueViolation):
+			raise Conflict(message="Service with this name already exists")
+	db.commit()
 	response = ServiceWithKeyResponse(**service_model.__dict__)
 	db.commit()
 	return {"service": response}