diff --git a/test/integration/admin_area/api_users_test.rb b/test/integration/admin_area/api_users_test.rb
index 3e0af7bad..70c70d7f3 100644
--- a/test/integration/admin_area/api_users_test.rb
+++ b/test/integration/admin_area/api_users_test.rb
@@ -38,4 +38,71 @@ class AdminAreaRegistrarsIntegrationTest < ActionDispatch::IntegrationTest
     assert_equal @api_user.accreditation_date.to_date, api_user.accreditation_date.to_date
     assert_equal @api_user.accreditation_expire_date.to_date, api_user.accreditation_expire_date.to_date
   end
+
+  def test_index_api_users
+    get admin_api_users_path
+    assert_response :success
+    
+    assert_select 'table'
+    assert_select 'table tr', minimum: 2
+  end
+
+  def test_index_api_users_with_registrar_id
+    get admin_api_users_path, params: {q: { registrar_id: @api_user.registrar_id } }
+    assert_response :success
+    assert_select 'table tr', minimum: 2
+  end
+
+  def test_index_with_pagination
+    get admin_api_users_path, params: { results_per_page: 1 }
+    assert_response :success
+  
+    assert_select 'table tr', minimum: 2
+    assert_select 'table tr', maximum: 2  
+    assert_select 'table tr', count: 2
+  end
+
+  def test_update_api_user_successfully
+    api_user = users(:api_bestnames)
+    new_username = 'updated_username'
+    
+    patch admin_registrar_api_user_path(api_user.registrar, api_user), 
+          params: { api_user: { username: new_username } }
+    
+    assert_redirected_to admin_registrar_api_user_path(api_user.registrar, api_user)
+    api_user.reload
+    assert_equal new_username, api_user.username
+  end
+
+  def test_update_api_user_with_invalid_data
+    api_user = users(:api_bestnames)
+    
+    patch admin_registrar_api_user_path(api_user.registrar, api_user), 
+          params: { api_user: { username: '' } }
+    
+    assert_response :success # Rails renders the form again with errors - 200
+    assert_select 'div.alert.alert-danger', /Username.*(missing|can't be blank)/i
+  end
+
+  def test_remove_test_date_from_api_user
+    api_user = users(:api_bestnames)
+    api_user.update_columns(
+      accreditation_date: Time.zone.now,
+      accreditation_expire_date: Time.zone.now + 1.year
+    )
+    
+    assert_not_nil api_user.accreditation_date
+    assert_not_nil api_user.accreditation_expire_date
+    
+    referer_path = admin_registrar_path(api_user.registrar)
+    post remove_test_date_to_api_user_admin_registrars_path(api_user.registrar), 
+         params: { user_api_id: api_user.id },
+         headers: { 'HTTP_REFERER' => referer_path }
+    
+    assert_redirected_to referer_path
+    
+    api_user.reload
+    assert_nil api_user.accreditation_date
+    assert_nil api_user.accreditation_expire_date
+  end
 end