I don’t know any reason why you cannot or should not give a thank-you acknowledgment letter to a business that makes non-cash donations to your charity. Gifts of services or use of facilities, of course, are not deductible, but gifts of stuff are. It should describe the gift, and its condition if personal property, and say whether any goods or services were received in return (and the value of such goods or services if provided in return). It should not put a value on the property transferred. It may or may not satisfy the donor’s need for acknowledgement to claim a charitable contribution deduction, but it cannot hurt.

Corporations have special rules for deductions of non-cash contributions.  (See Ready Reference Page: “Corporations Have Special Rules on Contributions.”)  S Corporations and partnerships must file a Form 8283 if they claim deductions for personal property with a value in excess of $500.  Regular C corporations don’t need the form unless they are claiming a deduction of more than $5000. Gifts of property for which a deduction of more than $5000 is claimed must generally be appraised by an independent appraiser.  (See Ready Reference Page: “IRS Requires Substantiation of Contributions.” Since the article was originally written, the Tax Code requires the charity to file a Form 8282 if the property is disposed of within three years of the donation. The old rule was two years.)