The sample acknowledgement letters for receipt of payment provided below can be used as format templates for official and personal purposes. What do you need to include in your donation acknowledgment letter?This is usually the last notice containing details of the debt, proof of the money owed, and consequences for non-payment. For this reason, we recommend that you always make a written record of your notices, along with proof of delivery. Members receiving overpayment letters must respond promptly, as they are given four weeks to do so.