diff --git a/litellm/proxy/proxy_server.py b/litellm/proxy/proxy_server.py
index b7f11ec270..db0bb735ba 100644
--- a/litellm/proxy/proxy_server.py
+++ b/litellm/proxy/proxy_server.py
@@ -871,6 +871,12 @@ async def proxy_startup_event(app: FastAPI):  # noqa: PLR0915
         redis_usage_cache=redis_usage_cache,
     )
 
+    ## Validate use_redis_transaction_buffer requires Redis cache ##
+    ProxyStartupEvent._validate_redis_transaction_buffer_config(
+        general_settings=general_settings,
+        redis_usage_cache=redis_usage_cache,
+    )
+
     ## SEMANTIC TOOL FILTER ##
     # Read litellm_settings from config for semantic filter initialization
     try:
@@ -5618,6 +5624,35 @@ class ProxyStartupEvent:
             llm_router=llm_router, redis_usage_cache=redis_usage_cache
         )
 
+    @staticmethod
+    def _validate_redis_transaction_buffer_config(
+        general_settings: dict,
+        redis_usage_cache: Optional[RedisCache],
+    ):
+        """
+        Validates that when use_redis_transaction_buffer is enabled,
+        a Redis cache is properly configured in litellm_settings.
+        """
+        from litellm.secret_managers.main import str_to_bool
+
+        _use_redis_transaction_buffer: Optional[Union[bool, str]] = (
+            general_settings.get("use_redis_transaction_buffer", False)
+        )
+        if isinstance(_use_redis_transaction_buffer, str):
+            _use_redis_transaction_buffer = str_to_bool(_use_redis_transaction_buffer)
+
+        if _use_redis_transaction_buffer and redis_usage_cache is None:
+            raise ValueError(
+                "`use_redis_transaction_buffer` is enabled in general_settings "
+                "but no Redis cache is configured. This will cause spend updates "
+                "to not be tracked. Add a Redis cache in litellm_settings:\n\n"
+                "litellm_settings:\n"
+                "  cache: true\n"
+                "  cache_params:\n"
+                "    type: redis\n"
+                "    url: os.environ/REDIS_URL\n"
+            )
+
     @classmethod
     async def _initialize_semantic_tool_filter(
         cls,
diff --git a/tests/test_litellm/proxy/db/db_transaction_queue/test_redis_update_buffer.py b/tests/test_litellm/proxy/db/db_transaction_queue/test_redis_update_buffer.py
index 2a380370c3..78e07c2967 100644
--- a/tests/test_litellm/proxy/db/db_transaction_queue/test_redis_update_buffer.py
+++ b/tests/test_litellm/proxy/db/db_transaction_queue/test_redis_update_buffer.py
@@ -1,7 +1,7 @@
 import json
 import os
 import sys
-from unittest.mock import AsyncMock, MagicMock, patch
+from unittest.mock import AsyncMock, MagicMock
 
 import pytest
 
@@ -10,6 +10,7 @@ sys.path.insert(
 )  # Adds the parent directory to the system path
 
 from litellm.proxy.db.db_transaction_queue.redis_update_buffer import RedisUpdateBuffer
+from litellm.proxy.proxy_server import ProxyStartupEvent
 from litellm.types.caching import RedisPipelineRpushOperation
 
 
@@ -192,3 +193,39 @@ async def test_get_all_transactions_from_redis_buffer_pipeline_no_redis():
     buffer = RedisUpdateBuffer(redis_cache=None)
     result = await buffer.get_all_transactions_from_redis_buffer_pipeline()
     assert result == (None, None, None, None, None, None, None)
+
+
+def test_validate_redis_transaction_buffer_raises_without_redis():
+    """
+    When use_redis_transaction_buffer=true but no Redis cache is configured,
+    the proxy should refuse to start with a clear error message.
+    """
+    with pytest.raises(ValueError, match="use_redis_transaction_buffer"):
+        ProxyStartupEvent._validate_redis_transaction_buffer_config(
+            general_settings={"use_redis_transaction_buffer": True},
+            redis_usage_cache=None,
+        )
+
+
+def test_validate_redis_transaction_buffer_passes_with_redis():
+    """
+    When use_redis_transaction_buffer=true and Redis cache is configured,
+    validation should pass without error.
+    """
+    # Should not raise
+    ProxyStartupEvent._validate_redis_transaction_buffer_config(
+        general_settings={"use_redis_transaction_buffer": True},
+        redis_usage_cache=MagicMock(),
+    )
+
+
+def test_validate_redis_transaction_buffer_passes_when_disabled():
+    """
+    When use_redis_transaction_buffer is not set or false,
+    validation should pass regardless of Redis configuration.
+    """
+    # Should not raise even without Redis
+    ProxyStartupEvent._validate_redis_transaction_buffer_config(
+        general_settings={},
+        redis_usage_cache=None,
+    )