An acknowledgment is one of the most common types of notarial acts, but it often confuses Notaries. Here are 5 steps to performing an acknowledgment.The form includes essential details such as the name of the signer, the date of the acknowledgment, and the notary's official signature and seal. The sample acknowledgement letters for receipt of payment provided below can be used as format templates for official and personal purposes. A good donor acknowledgment letter is both a transaction record and a donor engagement opportunity. Here's how to write one. Mail to: Arizona Department of Revenue • Unclaimed Property Unit • PO Box 29026 • Phoenix, AZ 85038-9026.