Dear :

We have received your check (No. ) for $ in payment of [goods/services].

You have apparently made a mistake with the amount of payment. As you will see in our invoice No. (copy enclosed), the total charge amounts to $ instead of $ as indicated in your check.

There's no need, however, to pay us separately for the surcharge; we will add it to next monthly statement. If you have any questions concerning this matter, please call me at [phone number].

Thank you for prompt payment.

Yours sincerely,

[name]

[title]