A few acknowledgment letter "best practices" are to: Draft a template. A gift acknowledgment letter weaves together your nonprofit's appreciation, engagement, and compliance efforts following a donor's generosity.A good donation acknowledgement letter will show donors how much you appreciate their support and help them understand the impact their generosity will have. What do you need to include in your donation acknowledgment letter? A donor acknowledgement letter should include a few specific items to assist the donor and help your organization comply with IRS regulations. Remember to include gift details, such as gift date and gift amount, in your acknowledgment letter to the donor. 3. Include the nonprofit's EIN so the the donor can to check the charity's tax-exempt status with the IRS.