Not a lawyer (or an accountant), but...

If you're a 501(c)(3) (nonprofit) organization, then I'd certainly mention that -- and the fact that donations can be tax deductible -- in your letter.

Then -- after receipt of the donation -- I'd send a thank you letter specifically recognizing the contribution and including your TAX ID #. That letter will serve as a receipt for the donor's tax records.

The original letter would not be a receipt.

Tim

When sending letters asking for auction donations, do you include your Tax ID # with your request?

Thanks for any help you can offer.
Crystal