diff --git a/litellm/budget_manager.py b/litellm/budget_manager.py
index dcb5a7cc183..742f648d224 100644
--- a/litellm/budget_manager.py
+++ b/litellm/budget_manager.py
@@ -100,8 +100,10 @@ class BudgetManager:
         return self.user_dict[user]
 
     def projected_cost(self, model: str, messages: list, user: str):
-        text: Final = "".join(message["content"] for message in messages)
-        prompt_tokens: Final = litellm.token_counter(model=model, text=text)
+        # Fixed image estimate: a budget check must never fetch remote
+        # image URLs (unbounded/chunked bodies exhaust memory, and a check
+        # should not do network I/O at all).
+        prompt_tokens: Final = litellm.token_counter(model=model, messages=messages, use_default_image_token_count=True)
         prompt_cost, _ = litellm.cost_per_token(model=model, prompt_tokens=prompt_tokens, completion_tokens=0)
         current_cost: Final = self.user_dict[user].get("current_cost", 0)
         projected_cost: Final = prompt_cost + current_cost
diff --git a/tests/test_litellm/test_budget_manager.py b/tests/test_litellm/test_budget_manager.py
new file mode 100644
index 00000000000..ac645b55035
--- /dev/null
+++ b/tests/test_litellm/test_budget_manager.py
@@ -0,0 +1,93 @@
+import pytest
+
+from litellm.budget_manager import BudgetManager
+
+
+@pytest.fixture()
+def manager(tmp_path, monkeypatch) -> BudgetManager:
+    # BudgetManager persists to ./user_cost.json via a background thread;
+    # isolate cwd so the suite never litters the repo or races parallel workers.
+    monkeypatch.chdir(tmp_path)
+    bm = BudgetManager(project_name="test", client_type="local")
+    bm.create_budget(total_budget=10, user="u", duration="daily")
+    return bm
+
+
+def test_projected_cost_string_content(manager: BudgetManager):
+    cost = manager.projected_cost(
+        model="gpt-4o-mini",
+        messages=[{"role": "user", "content": "hello"}],
+        user="u",
+    )
+    assert cost > 0
+
+
+def test_projected_cost_vision_content(manager: BudgetManager):
+    cost = manager.projected_cost(
+        model="gpt-4o-mini",
+        messages=[
+            {
+                "role": "user",
+                "content": [
+                    {"type": "text", "text": "hi"},
+                    {"type": "image_url", "image_url": {"url": "http://x/y.png"}},
+                ],
+            }
+        ],
+        user="u",
+    )
+    assert cost > 0
+
+
+def test_projected_cost_none_and_missing_content(manager: BudgetManager):
+    assert (
+        manager.projected_cost(
+            model="gpt-4o-mini",
+            messages=[{"role": "assistant", "content": None}],
+            user="u",
+        )
+        >= 0
+    )
+    assert manager.projected_cost(model="gpt-4o-mini", messages=[{"role": "user"}], user="u") >= 0
+
+
+def test_projected_cost_tool_calls_with_null_content(manager: BudgetManager):
+    # The expensive shape: assistant turn carrying tool calls and no text.
+    cost = manager.projected_cost(
+        model="gpt-4o-mini",
+        messages=[
+            {"role": "user", "content": "what is the weather?"},
+            {
+                "role": "assistant",
+                "content": None,
+                "tool_calls": [
+                    {
+                        "id": "call_1",
+                        "type": "function",
+                        "function": {"name": "get_weather", "arguments": '{"city": "Paris"}'},
+                    }
+                ],
+            },
+        ],
+        user="u",
+    )
+    assert cost > 0
+
+
+def test_projected_cost_provider_specific_fields(manager: BudgetManager):
+    # Provider extras (name, cache_control, reasoning_content) must not break counting.
+    cost = manager.projected_cost(
+        model="gpt-4o-mini",
+        messages=[
+            {"role": "user", "content": "hi", "name": "soroush"},
+            {
+                "role": "assistant",
+                "content": [
+                    {"type": "text", "text": "hello", "cache_control": {"type": "ephemeral"}},
+                ],
+                "reasoning_content": "thinking...",
+            },
+        ],
+        user="u",
+    )
+    assert cost > 0