What do you need to include in your donation acknowledgment letter? This guide offers tips for writing acknowledgement letters to families for donations made in memory of a loved one.Giving receipts is an important practice since 501(c)(3) donations are tax-deductible to the donor. Our sample form provides an easy way to get started. This step-by-step guide will help you fill out the donation tax receipt and get things in order for tax season. Learn how to easily create your donation receipts and the best practices to follow in writing a great one. How do you acknowledge donations to your nonprofit organizations? What are you required to put on the tax receipt? A donation acknowledgment letter (sometimes called a donation receipt or thankyou letter) is an email or paper that recognizes a charitable contribution. When communicating the impact of memorial donations, be specific about how the donations you've received will further your cause.