Looking for an easy way to create fundraising letters? This guide and free templates empower you to effectively communicate needs and inspire support!What do you need to include in your donation acknowledgment letter? Gather all information required to complete the form. Have a valid form of payment. In this post, I'm breaking down how to write a donation letter. Include the nonprofit's EIN so the the donor can to check the charity's tax-exempt status with the IRS. As you review your letter, put yourself in the mind of your audience. Managers tend to keep busy, so long in-kind donation letters are out of the question! Think of your in-kind appeal letter as an elevator pitch.