diff --git a/test/integration/registrar/billing/balance_top_up_test.rb b/test/integration/registrar/billing/balance_top_up_test.rb
index c4dd1cf5d..36109e4c4 100644
--- a/test/integration/registrar/billing/balance_top_up_test.rb
+++ b/test/integration/registrar/billing/balance_top_up_test.rb
@@ -5,12 +5,20 @@ class BalanceTopUpTest < ActionDispatch::IntegrationTest
     login_as users(:api_bestnames)
   end
 
-  def test_registrar_balance_top_up
+  def test_creates_new_invoice
     visit registrar_invoices_url
     click_link_or_button 'Add deposit'
-    fill_in 'Amount', with: 100
-    click_link_or_button 'Add'
+    fill_in 'Amount', with: '25.5'
 
+    Registry.instance.stub(:vat_rate, 10) do
+      assert_difference 'Invoice.count' do
+        click_link_or_button 'Add'
+      end
+    end
+
+    invoice = Invoice.last
+
+    assert_equal BigDecimal('28.05'), invoice.sum_cache
     assert_text 'Please pay the following invoice'
   end
 end