diff --git a/plugins/catalog-react/src/components/UserListPicker/useAllEntitiesCount.test.tsx b/plugins/catalog-react/src/components/UserListPicker/useAllEntitiesCount.test.tsx
new file mode 100644
index 0000000000..61c2c6eb0a
--- /dev/null
+++ b/plugins/catalog-react/src/components/UserListPicker/useAllEntitiesCount.test.tsx
@@ -0,0 +1,106 @@
+/*
+ * Copyright 2023 The Backstage Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+import React, { PropsWithChildren } from 'react';
+import { CatalogApi } from '@backstage/catalog-client';
+import { useAllEntitiesCount } from './useAllEntitiesCount';
+import { waitFor } from '@testing-library/react';
+import { renderHook } from '@testing-library/react-hooks';
+import { EntityListProvider, useEntityList } from '../../hooks';
+import { catalogApiRef } from '../../api';
+import { ApiRef } from '@backstage/core-plugin-api';
+import { MemoryRouter } from 'react-router-dom';
+import { EntityOwnerFilter } from '../../filters';
+import { useMountEffect } from '@react-hookz/web';
+
+const mockQueryEntities: jest.MockedFn<CatalogApi['queryEntities']> = jest.fn();
+const mockCatalogApi: jest.Mocked<Partial<CatalogApi>> = {
+  queryEntities: mockQueryEntities,
+};
+
+jest.mock('@backstage/core-plugin-api', () => {
+  const actual = jest.requireActual('@backstage/core-plugin-api');
+  return {
+    ...actual,
+    useApi: (ref: ApiRef<any>) =>
+      ref === catalogApiRef ? mockCatalogApi : actual.useApi(ref),
+  };
+});
+
+describe('useAllEntitiesCount', () => {
+  beforeEach(() => {
+    jest.clearAllMocks();
+  });
+
+  it('should return the count', async () => {
+    mockQueryEntities.mockResolvedValue({
+      items: [],
+      totalItems: 10,
+      pageInfo: {},
+    });
+
+    function WrapFilters(props: PropsWithChildren<{}>) {
+      const { updateFilters } = useEntityList();
+
+      useMountEffect(() => {
+        updateFilters({
+          owners: new EntityOwnerFilter(['user:default/owner']),
+        });
+      });
+      return <>{props.children}</>;
+    }
+
+    const { result } = renderHook(() => useAllEntitiesCount(), {
+      wrapper: ({ children }) => (
+        <MemoryRouter>
+          <EntityListProvider>
+            <WrapFilters>{children}</WrapFilters>
+          </EntityListProvider>
+        </MemoryRouter>
+      ),
+    });
+
+    await waitFor(() =>
+      expect(mockQueryEntities).toHaveBeenCalledWith({
+        filter: {
+          'relations.ownedBy': ['user:default/owner'],
+        },
+        limit: 0,
+      }),
+    );
+    expect(result.current).toEqual({ count: 10, loading: false });
+  });
+
+  it(`shouldn't invoke the endpoint at startup, when filters are missing`, async () => {
+    mockQueryEntities.mockResolvedValue({
+      items: [],
+      totalItems: 10,
+      pageInfo: {},
+    });
+
+    const { result } = renderHook(() => useAllEntitiesCount(), {
+      wrapper: ({ children }) => (
+        <MemoryRouter>
+          <EntityListProvider>{children}</EntityListProvider>
+        </MemoryRouter>
+      ),
+    });
+
+    await expect(
+      waitFor(() => expect(mockQueryEntities).toHaveBeenCalled()),
+    ).rejects.toThrow();
+    expect(result.current).toEqual({ count: 0, loading: false });
+  });
+});