In the case of a purchaser claiming partial exemption from sales tax on the purchase of a trailer pursuant to 68 O.S. § 1355(2), the vendor should obtain a statement, signed by the purchaser, or by a person who may legally bind the purchaser, that Oklahoma vehicle excise tax and state sales tax at the rate of 1.25% will be paid on the purchase of the trailer in accordance with the provisions of Articles 13 and 21 of Title 68 of the Oklahoma Statutes, and that if the taxes are not so paid, the purchaser will be responsible for the state sales tax at the 4.5% rate and any applicable local sales tax due.
Okla. Admin. Code § 710:65-7-14