diff --git a/cognee/modules/data/methods/get_unique_data_id.py b/cognee/modules/data/methods/get_unique_data_id.py
index 3fc184ce4..877b5930c 100644
--- a/cognee/modules/data/methods/get_unique_data_id.py
+++ b/cognee/modules/data/methods/get_unique_data_id.py
@@ -1,5 +1,4 @@
 from uuid import uuid5, NAMESPACE_OID, UUID
-from typing import Optional
 from sqlalchemy import select
 
 from cognee.modules.data.models.Data import Data
@@ -7,7 +6,7 @@ from cognee.infrastructure.databases.relational import get_relational_engine
 from cognee.modules.users.models import User
 
 
-async def get_unique_data_id(data_identifier: str, user: User, tenant_id: Optional[UUID]) -> UUID:
+async def get_unique_data_id(data_identifier: str, user: User) -> UUID:
     """
     Function returns a unique UUID for data based on data identifier, user id and tenant id.
     If data with legacy ID exists, return that ID to maintain compatibility.
@@ -35,7 +34,7 @@ async def get_unique_data_id(data_identifier: str, user: User, tenant_id: Option
         # return UUID hash of file contents + owner id + tenant_id
         return uuid5(NAMESPACE_OID, f"{data_identifier}{str(user.id)}")
 
-    def _get_modern_unique_data_id(data_identifier: str, user: User, tenant_id: UUID) -> UUID:
+    def _get_modern_unique_data_id(data_identifier: str, user: User) -> UUID:
         """
         Function returns a unique UUID for data based on data identifier, user id and tenant id.
         Args:
@@ -47,13 +46,11 @@ async def get_unique_data_id(data_identifier: str, user: User, tenant_id: Option
             UUID: Unique identifier for the data
         """
         # return UUID hash of file contents + owner id + tenant_id
-        return uuid5(NAMESPACE_OID, f"{data_identifier}{str(user.id)}{str(tenant_id)}")
+        return uuid5(NAMESPACE_OID, f"{data_identifier}{str(user.id)}{str(user.tenant_id)}")
 
     # Get all possible data_id values
     data_id = {
-        "modern_data_id": _get_modern_unique_data_id(
-            data_identifier=data_identifier, user=user, tenant_id=tenant_id
-        ),
+        "modern_data_id": _get_modern_unique_data_id(data_identifier=data_identifier, user=user),
         "legacy_data_id": _get_deprecated_unique_data_id(
             data_identifier=data_identifier, user=user
         ),
diff --git a/cognee/modules/data/methods/get_unique_dataset_id.py b/cognee/modules/data/methods/get_unique_dataset_id.py
index 2caf5fb55..274f24d1a 100644
--- a/cognee/modules/data/methods/get_unique_dataset_id.py
+++ b/cognee/modules/data/methods/get_unique_dataset_id.py
@@ -1,9 +1,71 @@
 from uuid import UUID, uuid5, NAMESPACE_OID
-from cognee.modules.users.models import User
 from typing import Union
+from sqlalchemy import select
+
+from cognee.modules.data.models.Dataset import Dataset
+from cognee.modules.users.models import User
+from cognee.infrastructure.databases.relational import get_relational_engine
 
 
 async def get_unique_dataset_id(dataset_name: Union[str, UUID], user: User) -> UUID:
-    if isinstance(dataset_name, UUID):
-        return dataset_name
-    return uuid5(NAMESPACE_OID, f"{dataset_name}{str(user.id)}")
+    """
+    Function returns a unique UUID for dataset based on dataset name, user id and tenant id.
+    If dataset with legacy ID exists, return that ID to maintain compatibility.
+
+    Args:
+        dataset_name: string representing the dataset name
+        user: User object adding the dataset
+        tenant_id: UUID of the tenant for which dataset is being added
+
+    Returns:
+        UUID: Unique identifier for the dataset
+    """
+
+    def _get_legacy_unique_dataset_id(dataset_name: Union[str, UUID], user: User) -> UUID:
+        """
+        Legacy function, returns a unique UUID for dataset based on dataset name and user id.
+        Needed to support legacy datasets without tenant information.
+        Args:
+            dataset_name: string representing the dataset name
+            user: Current User object adding the dataset
+
+        Returns:
+            UUID: Unique identifier for the dataset
+        """
+        if isinstance(dataset_name, UUID):
+            return dataset_name
+        return uuid5(NAMESPACE_OID, f"{dataset_name}{str(user.id)}")
+
+    def _get_modern_unique_dataset_id(dataset_name: Union[str, UUID], user: User) -> UUID:
+        """
+        Returns a unique UUID for dataset based on dataset name, user id and tenant_id.
+        Args:
+            dataset_name: string representing the dataset name
+            user: Current User object adding the dataset
+            tenant_id: UUID of the tenant for which dataset is being added
+
+        Returns:
+            UUID: Unique identifier for the dataset
+        """
+        if isinstance(dataset_name, UUID):
+            return dataset_name
+        return uuid5(NAMESPACE_OID, f"{dataset_name}{str(user.id)}{str(user.tenant_id)}")
+
+    # Get all possible dataset_id values
+    dataset_id = {
+        "modern_dataset_id": _get_modern_unique_dataset_id(dataset_name=dataset_name, user=user),
+        "legacy_dataset_id": _get_legacy_unique_dataset_id(dataset_name=dataset_name, user=user),
+    }
+
+    # Check if dataset with legacy_dataset_id exists, if so use that one, else use modern_dataset_id
+    db_engine = get_relational_engine()
+    async with db_engine.get_async_session() as session:
+        legacy_dataset = (
+            await session.execute(
+                select(Dataset).filter(Dataset.id == dataset_id["legacy_data_id"])
+            )
+        ).scalar_one_or_none()
+
+        if not legacy_dataset:
+            return dataset_id["modern_dataset_id"]
+        return dataset_id["legacy_dataset_id"]
diff --git a/cognee/modules/ingestion/identify.py b/cognee/modules/ingestion/identify.py
index 5a0fe379e..640fce4a2 100644
--- a/cognee/modules/ingestion/identify.py
+++ b/cognee/modules/ingestion/identify.py
@@ -8,6 +8,4 @@ from cognee.modules.data.methods import get_unique_data_id
 async def identify(data: IngestionData, user: User) -> UUID:
     data_content_hash: str = data.get_identifier()
 
-    return await get_unique_data_id(
-        data_identifier=data_content_hash, user=user, tenant_id=user.tenant_id
-    )
+    return await get_unique_data_id(data_identifier=data_content_hash, user=user)