What do you need to include in your donation acknowledgment letter? A gift acknowledgment letter weaves together your nonprofit's appreciation, engagement, and compliance efforts following a donor's generosity.This easy-to-navigate guide for using personalized handwritten notes in fundraising helps charities earn more donations. With free templates! Include the nonprofit's EIN so the the donor can to check the charity's tax-exempt status with the IRS. Gift acknowledgement letters are important for two reasons. First, they provide proof so donors can claim a US tax exemption. The Marlins donate autographed memorabilia and ticket certificates in an effort to support charitable organizations that positively impact our community. A donation acknowledgment letter (sometimes called a donation receipt or thankyou letter) is an email or paper that recognizes a charitable contribution. Eligibility for nonprofit organizations.