What do you need to include in your donation acknowledgment letter? A gift acknowledgment letter recognizes donors and can be used to claim tax deductions.Gift acknowledgement letters are important for two reasons. First, they provide proof so donors can claim a U.S. tax exemption. Prompt and thoughtful gift acknowledgments are central to effective fundraising. Take a look at what makes a good thank you letter for a donation or use one of our provided templates to help get you started. First paragraph: Immediately thank donors for their gift. Include the nonprofit's EIN so the the donor can to check the charity's tax-exempt status with the IRS.