How To Write A Donation Request Letter For A Nonprofit . This is a formal letter which is written to request a donation. We have written an article on writing fundraising letters in the past. Download Donation Request Letter Excel Template ExcelDataPro from exceldatapro.com Here is a sample of the letter. Notice that, even though this request is a letter, it is concrete. Whenever possible with a mailing, sign the bottom with ink instead of just typing the name at the bottom.