What do you need to include in your donation acknowledgment letter? A donation acknowledgment letter (sometimes called a donation receipt or thankyou letter) is an email or paper that recognizes a charitable contribution.Learn how to easily create your donation receipts and the best practices to follow in the year-end receipts to your donors. When acknowledging these donations, include the name of the donor, the number of shares, the name of the security, and the date when the transfer was completed. Acknowledgement letters should be mailed no later than one week (57 business days) from the date of the gift. Looking for an easy way to create fundraising letters? This guide and free templates empower you to effectively communicate needs and inspire support!