(a) Except as provided by Subsection (d) of this section, all gross receipts of a seller are presumed to have been subject to the sales tax unless a properly completed resale or exemption certificate is accepted by the seller.
(b) A sale is exempt if the seller receives in good faith from a purchaser, who is in the business of selling, leasing, or renting taxable items, a resale certificate stating that the tangible personal property or service is acquired for the purpose of selling, leasing, or renting it in the regular course of business or for the purpose of transferring it as an integral part of a taxable service performed in the regular course of business.

(c) A sale is exempt if the seller receives in good faith from a purchaser an exemption certificate stating qualifications for an exemption provided in Subchapter H of this chapter.
(d) A sale of liquor, wine, or malt beverages by the holder of a brewer’s license, wholesaler’s permit, general class B wholesaler’s permit, local distributor’s permit, or a general or branch distributor’s license issued under the Alcoholic Beverage Code to the holder of a retail license or permit issued under the Alcoholic Beverage Code is presumed to be a sale for resale. In a sale to which this section applies, the seller is not required to receive a resale certificate from the purchaser.
(e) Properly completed resale or exemption certificates should be in the possession of the seller at the time the nontaxable transaction occurs. If the seller is not in possession of these certificates within 90 days from the date written notice requiring possession of them is given to the seller by the comptroller or a later date agreed to by the comptroller and the seller, deductions claimed by the seller that require delivery of the certificates shall be disallowed. A deduction may not be granted on the basis of certificates delivered to the comptroller after the 90-day period or, if applicable, the date agreed to by the comptroller and the seller.
(f) Before allowing a deduction, the comptroller may verify the reason or basis for exemption claimed in a resale or exemption certificate delivered to the comptroller during the period provided by Subsection (e).