Write an excellent thank you letter for donations. Get tips and best practices, plus three inspiring samples and ready to use templates!"Your generous donation has made it possible for us to provide essential services to those in need. We are deeply grateful for your support. What is required in a donation acknowledgement letter? Thank you notes for nonprofits are vital. There are obvious benefits and some bonus benefits. Complete the in-kind donation form, click "Submit", then "Click here to send your ecard". Donation Form: Complete the online donation form here. This form lets us know when you are ready send us your letters.