What do you need to include in your donation acknowledgment letter? Find out what the IRS requires, what donors expect, and our recommendations for acknowledging contributions.A gift acknowledgment letter weaves together your nonprofit's appreciation, engagement, and compliance efforts following a donor's generosity. A donor acknowledgement letter should include a few specific items to assist the donor and help your organization comply with IRS regulations. Acknowledgment of "no goods or services were provided as part of this donation. There is no official IRS form that the exempt organization has to complete. When does the nonprofit need to send the written acknowledgment letter to donors? Note: The Anatomy Bequest Program cannot accept a donation unless a fully executed consent form is complete.