diff --git a/litellm/models/team.py b/litellm/models/team.py
index da526515e6e..2e7709a0c94 100644
--- a/litellm/models/team.py
+++ b/litellm/models/team.py
@@ -10,7 +10,7 @@ import json
 from datetime import datetime
 from typing import Final, Literal, Optional
 
-from pydantic import BaseModel, ConfigDict, Field, model_validator
+from pydantic import BaseModel, ConfigDict, Field, field_validator, model_validator
 
 from litellm.models.object_permission import LiteLLM_ObjectPermissionTable
 from litellm.types.llms.base import LiteLLMPydanticObjectBase
@@ -81,6 +81,13 @@ class TeamBase(LiteLLMPydanticObjectBase):
     access_group_ids: list[str] | None = None
     default_team_member_models: list[str] | None = None
 
+    @field_validator("budget_duration", mode="before")
+    @classmethod
+    def check_budget_duration(cls, v):
+        if isinstance(v, str) and v.strip() == "":
+            return None
+        return v
+
 
 class LiteLLM_TeamTable(TeamBase):
     team_id: str
diff --git a/litellm/proxy/_types.py b/litellm/proxy/_types.py
index ed49ca2caa9..70325ba91e6 100644
--- a/litellm/proxy/_types.py
+++ b/litellm/proxy/_types.py
@@ -1106,6 +1106,12 @@ from litellm.types.object_permission import (  # noqa: E402
 )
 
 
+def normalize_empty_budget_duration(value: Optional[str]) -> Optional[str]:
+    if isinstance(value, str) and value.strip() == "":
+        return None
+    return value
+
+
 class GenerateRequestBase(LiteLLMPydanticObjectBase):
     """
     Overlapping schema between key and user generate/update requests
@@ -1151,6 +1157,11 @@ class GenerateRequestBase(LiteLLMPydanticObjectBase):
             return None
         return v
 
+    @field_validator("budget_duration", mode="before")
+    @classmethod
+    def check_budget_duration(cls, v):
+        return normalize_empty_budget_duration(v)
+
 
 class AllowedVectorStoreIndexItem(LiteLLMPydanticObjectBase):
     index_name: str
@@ -1787,6 +1798,11 @@ class BudgetNewRequest(LiteLLMPydanticObjectBase):
         description="Datetime when the budget is reset",
     )
 
+    @field_validator("budget_duration", mode="before")
+    @classmethod
+    def check_budget_duration(cls, v):
+        return normalize_empty_budget_duration(v)
+
 
 class BudgetRequest(LiteLLMPydanticObjectBase):
     budgets: list[str]
@@ -1980,6 +1996,11 @@ class PatchTeamRequest(UpdateTeamRequest):
 
     team_id: str | None = None
 
+    @field_validator("budget_duration", mode="before")
+    @classmethod
+    def check_budget_duration(cls, v):
+        return normalize_empty_budget_duration(v)
+
 
 class ResetTeamBudgetRequest(LiteLLMPydanticObjectBase):
     """
diff --git a/tests/test_litellm/proxy/management_endpoints/test_internal_user_endpoints.py b/tests/test_litellm/proxy/management_endpoints/test_internal_user_endpoints.py
index 8bce967b316..864ff142f00 100644
--- a/tests/test_litellm/proxy/management_endpoints/test_internal_user_endpoints.py
+++ b/tests/test_litellm/proxy/management_endpoints/test_internal_user_endpoints.py
@@ -2079,6 +2079,41 @@ def test_generate_request_base_validator():
     assert req.max_budget is None
 
 
+def test_generate_request_base_normalizes_empty_budget_duration():
+    """
+    Regression test for https://github.com/BerriAI/litellm/issues/32474
+
+    Clearing budget_duration from the UI sends an empty string; downstream duration
+    parsing rejects "" with "Invalid duration format". The request model must normalize
+    empty/whitespace-only values to None so resetting a budget to unlimited succeeds.
+    """
+    from litellm.proxy._types import GenerateRequestBase
+
+    assert GenerateRequestBase(budget_duration="").budget_duration is None
+    assert GenerateRequestBase(budget_duration="   ").budget_duration is None
+    assert GenerateRequestBase(budget_duration=None).budget_duration is None
+    assert GenerateRequestBase(budget_duration="30d").budget_duration == "30d"
+
+
+def test_update_internal_user_params_reset_budget_duration_to_unlimited():
+    """
+    Regression test for https://github.com/BerriAI/litellm/issues/32474
+
+    Sending an empty budget_duration alongside an empty max_budget (what the UI sends
+    when resetting a user's budget to unlimited) must not raise "Invalid duration format"
+    and must not fabricate a budget_reset_at.
+    """
+    data = UpdateUserRequest(user_id="test_user", max_budget="", budget_duration="")
+    assert data.max_budget is None
+    assert data.budget_duration is None
+
+    non_default_values = _update_internal_user_params(data_json=data.model_dump(exclude_unset=True), data=data)
+
+    assert non_default_values["max_budget"] is None
+    assert non_default_values.get("budget_duration") is None
+    assert "budget_reset_at" not in non_default_values
+
+
 @pytest.mark.asyncio
 async def test_get_user_daily_activity_non_admin_cannot_view_other_users(monkeypatch):
     """
diff --git a/tests/test_litellm/proxy/test_proxy_types.py b/tests/test_litellm/proxy/test_proxy_types.py
index 634b90e445a..75e92c0874a 100644
--- a/tests/test_litellm/proxy/test_proxy_types.py
+++ b/tests/test_litellm/proxy/test_proxy_types.py
@@ -102,6 +102,32 @@ def test_user_api_key_auth_hashes_authorization_header_form_of_key():
         assert not from_header.api_key.lower().startswith("bearer")
 
 
+@pytest.mark.parametrize(
+    "model_name, extra_kwargs",
+    [
+        ("GenerateKeyRequest", {}),
+        ("NewUserRequest", {}),
+        ("UpdateUserRequest", {"user_id": "u1"}),
+        ("NewCustomerRequest", {"user_id": "c1"}),
+        ("NewTeamRequest", {}),
+        ("UpdateTeamRequest", {"team_id": "t1"}),
+    ],
+)
+def test_request_models_normalize_empty_budget_duration(model_name, extra_kwargs):
+    """Regression for https://github.com/BerriAI/litellm/issues/32474: clearing a budget
+    from the UI sends budget_duration="", which downstream duration parsing rejects with
+    "Invalid duration format". Request models must coerce empty/whitespace values to None
+    while leaving real durations untouched."""
+    import litellm.proxy._types as proxy_types
+
+    model = getattr(proxy_types, model_name)
+
+    assert model(budget_duration="", **extra_kwargs).budget_duration is None
+    assert model(budget_duration="   ", **extra_kwargs).budget_duration is None
+    assert model(budget_duration=None, **extra_kwargs).budget_duration is None
+    assert model(budget_duration="30d", **extra_kwargs).budget_duration == "30d"
+
+
 def test_proxy_exception_str_returns_message():
     """ProxyException must stringify to its message: OTEL's
     ``span.record_exception`` and ``str(exc)``-based logging read the string