diff --git a/litellm/proxy/auth/auth_utils.py b/litellm/proxy/auth/auth_utils.py
index c868d3d22b2..c8c0ce6c8e1 100644
--- a/litellm/proxy/auth/auth_utils.py
+++ b/litellm/proxy/auth/auth_utils.py
@@ -1113,6 +1113,9 @@ def _coerce_user_id_to_str(value: Any) -> Optional[str]:
 def get_end_user_id_from_request_body(
     request_body: dict, request_headers: Optional[dict] = None
 ) -> Optional[str]:
+    if litellm.disable_end_user_cost_tracking:
+        return None
+
     # Import general_settings here to avoid potential circular import issues at module level
     # and to ensure it's fetched at runtime.
     from litellm.proxy.proxy_server import general_settings
diff --git a/litellm/proxy/spend_tracking/spend_tracking_utils.py b/litellm/proxy/spend_tracking/spend_tracking_utils.py
index d215294fd04..ba86c41964f 100644
--- a/litellm/proxy/spend_tracking/spend_tracking_utils.py
+++ b/litellm/proxy/spend_tracking/spend_tracking_utils.py
@@ -298,9 +298,10 @@ def get_logging_payload(  # noqa: PLR0915
             or standard_logging_payload["metadata"].get("user_api_key_hash")
             or ""
         )
-        end_user_id = end_user_id or standard_logging_payload["metadata"].get(
-            "user_api_key_end_user_id"
-        )
+        if not litellm.disable_end_user_cost_tracking:
+            end_user_id = end_user_id or standard_logging_payload["metadata"].get(
+                "user_api_key_end_user_id"
+            )
     # BUG FIX: Don't overwrite api_key when standard_logging_payload is None
     # The api_key was already extracted from metadata (line 243) and hashed (lines 256-259)
     request_tags = (
diff --git a/tests/proxy_unit_tests/test_disable_end_user_cost_tracking_proxy.py b/tests/proxy_unit_tests/test_disable_end_user_cost_tracking_proxy.py
new file mode 100644
index 00000000000..e7350eddbb1
--- /dev/null
+++ b/tests/proxy_unit_tests/test_disable_end_user_cost_tracking_proxy.py
@@ -0,0 +1,85 @@
+import pytest
+import asyncio
+import os, sys
+from unittest.mock import MagicMock, patch
+
+# Add the project root to sys.path
+sys.path.insert(0, os.path.abspath(os.path.join(os.path.dirname(__file__), "../../")))
+
+import litellm
+from litellm.proxy.spend_tracking.spend_tracking_utils import get_logging_payload
+from datetime import datetime
+
+@pytest.mark.asyncio
+async def test_get_logging_payload_honors_disable_flag():
+    """
+    Test that get_logging_payload correctly suppresses end_user_id 
+    when litellm.disable_end_user_cost_tracking is True.
+    """
+    # 1. Setup
+    litellm.disable_end_user_cost_tracking = True
+    
+    kwargs = {
+        "litellm_params": {
+            "metadata": {
+                "user_api_key_end_user_id": "test-user-123"
+            }
+        },
+        "call_type": "completion",
+        "standard_logging_object": {
+            "metadata": {
+                "user_api_key_end_user_id": "test-user-123"
+            },
+            "prompt_tokens": 10,
+            "completion_tokens": 5,
+            "total_tokens": 15,
+            "model_map_information": {}
+        }
+    }
+    
+    response_obj = {"id": "chatcmpl-123", "usage": {"total_tokens": 15}}
+    start_time = datetime.now()
+    end_time = datetime.now()
+    
+    # 2. Execute
+    payload = get_logging_payload(kwargs, response_obj, start_time, end_time)
+    
+    # 3. Assert
+    assert payload["end_user"] == ""
+    
+    # 4. Cleanup
+    litellm.disable_end_user_cost_tracking = False
+
+@pytest.mark.asyncio
+async def test_get_logging_payload_tracks_when_not_disabled():
+    """
+    Test that get_logging_payload correctly includes end_user_id 
+    when litellm.disable_end_user_cost_tracking is False.
+    """
+    # 1. Setup
+    litellm.disable_end_user_cost_tracking = False
+    
+    kwargs = {
+        "litellm_params": {
+            "metadata": {
+                "user_api_key_end_user_id": "test-user-456"
+            }
+        },
+        "call_type": "completion",
+        "standard_logging_object": {
+            "metadata": {
+                "user_api_key_end_user_id": "test-user-456"
+            },
+            "model_map_information": {}
+        }
+    }
+    
+    response_obj = {"id": "chatcmpl-456"}
+    start_time = datetime.now()
+    end_time = datetime.now()
+    
+    # 2. Execute
+    payload = get_logging_payload(kwargs, response_obj, start_time, end_time)
+    
+    # 3. Assert
+    assert payload["end_user"] == "test-user-456"