Donation acknowledgment letters are more than just a donor tax receipt. There are certain items to include for tax purposes.This step-by-step guide will help you fill out the donation tax receipt and get things in order for tax season. Knowing how to write an in-kind donation letter for your nonprofit means understanding the do's and don'ts. Let's check them out! A donor acknowledgement letter should include a few specific items to assist the donor and help your organization comply with IRS regulations. Donation receipts are important! Here's how to create donation receipts your donors (and the IRS) will love. Charitable contributions are generally taxdeductible if you itemize. Safe harbor for certain charitable contributions made in exchange for a state or local tax credit.