diff --git a/litellm/proxy/common_utils/reset_budget_job.py b/litellm/proxy/common_utils/reset_budget_job.py
index f2648c8466e..35e74418628 100644
--- a/litellm/proxy/common_utils/reset_budget_job.py
+++ b/litellm/proxy/common_utils/reset_budget_job.py
@@ -224,33 +224,31 @@ def _queue_budget_linked_resets(
 
 
 def _queue_enduser_resets(writes: LinkedSpendResetWrites, cascade: "_BudgetCascade") -> None:
-    """End users are matched by id rather than budget link: rows with no
-    budget_id ride the default budget tier (litellm.max_end_user_budget_id).
-    Zero-before-decrement ordering matters here too (see
-    _queue_budget_linked_resets)."""
-    if not cascade.rollover_caps:
-        if cascade.endusers:
-            writes.queue_spend_zero(
-                where={"user_id": {"in": [row.user_id for row in cascade.endusers]}}
-            )  # mutable-ok: prisma where filter must be a dict
+    """End users reset on the budget link like every other gated table, plus a
+    NULL-budget_id branch: rows created implicitly persist no link and ride the
+    default tier (litellm.max_end_user_budget_id).
+
+    Matching on the link rather than enumerating user ids keeps a statement's
+    bind count proportional to the expiring tiers instead of the customer
+    population, which past ~32,700 dependents exceeds PostgreSQL's per-statement
+    bind ceiling and wedges the cascade permanently (#40564).
+    """
+    _queue_budget_linked_resets(writes, cascade, extra=_SPENT_ROWS_WHERE)
+    default_budget_id: Final = litellm.max_end_user_budget_id
+    if default_budget_id is None or default_budget_id not in cascade.budget_ids:
         return
-    tiered: Final = tuple((row.budget_id or litellm.max_end_user_budget_id, row.user_id) for row in cascade.endusers)
-    for budget_id, cap in cascade.rollover_caps.items():
-        if not (
-            user_ids := [uid for bid, uid in tiered if bid == budget_id]
-        ):  # mutable-ok: prisma "in" filter takes a list
-            continue
+    cap: Final = cascade.rollover_caps.get(default_budget_id)
+    if cap is None:
         writes.queue_spend_zero(
-            where={"user_id": {"in": user_ids}, "spend": {"lte": cap}}
+            where={"budget_id": None, **_SPENT_ROWS_WHERE}
         )  # mutable-ok: prisma where filter must be a dict
-        writes.queue_spend_decrement(
-            where={"user_id": {"in": user_ids}, "spend": {"gt": cap}}, amount=cap
-        )  # mutable-ok: prisma where filter must be a dict
-    plain: Final = [
-        uid for bid, uid in tiered if bid is None or bid not in cascade.rollover_caps
-    ]  # mutable-ok: prisma "in" filter takes a list
-    if plain:
-        writes.queue_spend_zero(where={"user_id": {"in": plain}})  # mutable-ok: prisma where filter must be a dict
+        return
+    writes.queue_spend_zero(
+        where={"budget_id": None, "spend": {"gt": 0, "lte": cap}}
+    )  # mutable-ok: prisma where filter must be a dict
+    writes.queue_spend_decrement(
+        where={"budget_id": None, "spend": {"gt": cap}}, amount=cap
+    )  # mutable-ok: prisma where filter must be a dict
 
 
 @dataclass(frozen=True, slots=True)
diff --git a/tests/litellm_utils_tests/test_proxy_budget_reset.py b/tests/litellm_utils_tests/test_proxy_budget_reset.py
index 9f6e1f4c3f7..4103536950d 100644
--- a/tests/litellm_utils_tests/test_proxy_budget_reset.py
+++ b/tests/litellm_utils_tests/test_proxy_budget_reset.py
@@ -401,7 +401,7 @@ async def test_reset_budget_endusers_are_zeroed_with_the_budget_window_advance()
 
     enduser_writes = [c for c in batch_calls if c["table"] == "enduser"]
     assert len(enduser_writes) == 1
-    assert enduser_writes[0]["where"]["user_id"]["in"] == [f"user{i}" for i in range(1, 7)]
+    assert enduser_writes[0]["where"] == {"budget_id": {"in": ["budget1"]}, "spend": {"gt": 0}}
     assert enduser_writes[0]["data"] == {"spend": 0}
 
     budget_writes = [c for c in batch_calls if c["table"] == "budget"]
@@ -602,7 +602,7 @@ async def test_reset_budget_continues_other_categories_on_failure():
     assert len([c for c in batch_calls if c["table"] == "team_membership"]) == 1
     enduser_writes = [c for c in batch_calls if c["table"] == "enduser"]
     assert len(enduser_writes) == 1
-    assert enduser_writes[0]["where"] == {"user_id": {"in": ["user1"]}}
+    assert enduser_writes[0]["where"] == {"budget_id": {"in": ["budget1"]}, "spend": {"gt": 0}}
     assert enduser_writes[0]["data"] == {"spend": 0}
 
     # Check the new batch write path: 2 keys + 1 user (user1 failed) + 2 teams.
@@ -1031,7 +1031,7 @@ async def test_service_logger_endusers_success():
 
     enduser_writes = [c for c in batch_calls if c["table"] == "enduser"]
     assert len(enduser_writes) == 1
-    assert enduser_writes[0]["where"] == {"user_id": {"in": ["user1", "user2"]}}
+    assert enduser_writes[0]["where"] == {"budget_id": {"in": ["budget1"]}, "spend": {"gt": 0}}
 
     proxy_logging_obj.service_logging_obj.async_service_success_hook.assert_called_once()
     (
diff --git a/tests/test_litellm/proxy/common_utils/test_reset_budget_job.py b/tests/test_litellm/proxy/common_utils/test_reset_budget_job.py
index 56c0efb41d2..560953f0b51 100644
--- a/tests/test_litellm/proxy/common_utils/test_reset_budget_job.py
+++ b/tests/test_litellm/proxy/common_utils/test_reset_budget_job.py
@@ -403,7 +403,7 @@ def test_reset_budget_for_enduser(reset_budget_job, mock_prisma_client):
         {
             "table": "enduser",
             "op": "update_many",
-            "where": {"user_id": {"in": ["test-enduser-1"]}},
+            "where": {"budget_id": {"in": ["test-budget-1"]}, "spend": {"gt": 0}},
             "data": {"spend": 0},
         }
     ]
@@ -504,7 +504,7 @@ def test_reset_budget_all(reset_budget_job, mock_prisma_client):
         {
             "table": "enduser",
             "op": "update_many",
-            "where": {"user_id": {"in": ["test-enduser-1"]}},
+            "where": {"budget_id": {"in": ["test-budget-1"]}, "spend": {"gt": 0}},
             "data": {"spend": 0},
         }
     ]
@@ -524,6 +524,7 @@ _LINKED_TABLE_CASES = [
     ("org", {"budget_id": {"in": ["7d-budget-tier"]}, "spend": {"gt": 0}}),
     ("tag", {"budget_id": {"in": ["7d-budget-tier"]}, "spend": {"gt": 0}}),
     ("model_access_group", {"budget_id": {"in": ["7d-budget-tier"]}, "spend": {"gt": 0}}),
+    ("enduser", {"budget_id": {"in": ["7d-budget-tier"]}, "spend": {"gt": 0}}),
 ]
 
 
@@ -553,6 +554,48 @@ def test_budget_table_reset_zeroes_spend_on_every_linked_table(
     assert writes[0]["data"] == {"spend": 0}
 
 
+_POSTGRES_MAX_BIND_VARIABLES: Final = 32767
+
+
+def _bind_count(where: Dict[str, Any]) -> int:
+    """Bind variables one prisma where-clause compiles to: each scalar is one
+    placeholder and an ``in`` list contributes one per element."""
+    return sum(len(value["in"]) if isinstance(value, dict) and "in" in value else 1 for value in where.values())
+
+
+@pytest.mark.parametrize("population", [3, 40_000], ids=["small", "over-pg-bind-ceiling"])
+def test_enduser_reset_bind_count_does_not_scale_with_population(reset_budget_job, mock_prisma_client, population):
+    """Regression for #40564.
+
+    Enumerating every dependent user id put one bind variable per customer into
+    a single prepared statement. Past PostgreSQL's ceiling the statement could
+    not be parsed at all, so the whole atomic cascade rolled back,
+    budget_reset_at never advanced, and the tier stayed due on every later tick
+    forever. Matching on the budget link keeps the statement the same size no
+    matter how many customers share a tier.
+    """
+    budget = _budget_row(budget_id="shared-tier", budget_duration="1d")
+    mock_prisma_client.data["budget"] = [budget]
+    mock_prisma_client.data["enduser"] = [
+        types.SimpleNamespace(
+            spend=1.0,
+            litellm_budget_table=budget,
+            user_id=f"cust-{index:08d}",
+            budget_id="shared-tier",
+        )
+        for index in range(population)
+    ]
+
+    asyncio.run(reset_budget_job.reset_budget_for_litellm_budget_table())
+
+    writes = _batch_writes(mock_prisma_client, "enduser")
+    assert [_bind_count(write["where"]) for write in writes] == [2], (
+        f"the cascade must not enumerate {population} user ids: past "
+        f"{_POSTGRES_MAX_BIND_VARIABLES} binds PostgreSQL refuses the statement, got {writes[:1]}"
+    )
+    assert _batch_writes(mock_prisma_client, "budget")[0]["data"]["budget_reset_at"] is not None
+
+
 def test_budget_table_reset_writes_nothing_when_no_budget_is_due(reset_budget_job, mock_prisma_client):
     """Nothing due means no transaction is opened at all."""
     asyncio.run(reset_budget_job.reset_budget_for_litellm_budget_table())
@@ -720,14 +763,22 @@ def test_reset_budget_resets_endusers_with_null_budget_id(reset_budget_job, mock
 
     asyncio.run(reset_budget_job.reset_budget_for_litellm_budget_table())
 
-    # Both end users are zeroed by the same committed statement.
-    enduser_writes = _batch_writes(mock_prisma_client, "enduser")
-    assert len(enduser_writes) == 1, f"Expected a single enduser write, got {enduser_writes}"
-    assert set(enduser_writes[0]["where"]["user_id"]["in"]) == {
-        "enduser-explicit",
-        "enduser-implicit",
-    }
-    assert enduser_writes[0]["data"] == {"spend": 0}
+    # Both end users are zeroed: the linked rows on the tier's budget_id, the
+    # implicit ones on the NULL branch that stands in for the default tier.
+    assert _batch_writes(mock_prisma_client, "enduser") == [
+        {
+            "table": "enduser",
+            "op": "update_many",
+            "where": {"budget_id": {"in": [default_budget_id]}, "spend": {"gt": 0}},
+            "data": {"spend": 0},
+        },
+        {
+            "table": "enduser",
+            "op": "update_many",
+            "where": {"budget_id": None, "spend": {"gt": 0}},
+            "data": {"spend": 0},
+        },
+    ]
 
     # Verify find_many was called to fetch NULL-budget-id end users
     find_many_calls = mock_prisma_client.db.litellm_endusertable.find_many_calls
@@ -3043,13 +3094,13 @@ def test_budget_cascade_carries_enduser_overage_when_rollover_enabled(
     assert {
         "table": "enduser",
         "op": "update_many",
-        "where": {"user_id": {"in": ["enduser-roll"]}, "spend": {"gt": 10.0}},
+        "where": {"budget_id": "budget-roll", "spend": {"gt": 10.0}},
         "data": {"spend": {"decrement": 10.0}},
     } in enduser_writes
     assert {
         "table": "enduser",
         "op": "update_many",
-        "where": {"user_id": {"in": ["enduser-roll"]}, "spend": {"lte": 10.0}},
+        "where": {"budget_id": "budget-roll", "spend": {"gt": 0, "lte": 10.0}},
         "data": {"spend": 0},
     } in enduser_writes