The certificate of acknowledgment (PDF) must be in the form set forth in California Civil Code section 1189. 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? I want to acknowledge receipt of your message and express my appreciation for reaching out. After reviewing your rights described on the following pages, sign the acknowledgement that you have received the Buyout Agreement Disclosure. The City is requesting to obtain the services of an outside organization to help with City.