What do you need to include in your donation acknowledgment letter? Sample Donor Acknowledgement Letter for NonCash Donation.A gift acknowledgment letter recognizes donors and can be used to claim tax deductions. Donor acknowledgement letters are an essential engagement tool and tax exemption requirement. Prompt and thoughtful gift acknowledgments are central to effective fundraising. Include the nonprofit's EIN so the the donor can to check the charity's tax-exempt status with the IRS. Want to learn how to write and structure donor acknowledgment letters? Check out these tips and sample letters to make a greater impact. When someone donates to your organization, they're doing more than giving money. They're saying, "I believe in your mission.