Currently registered foreign semitrailers having a gross weight in excess of 6,000 pounds used or to be used in combination with commercial motor vehicles or truck tractors having a gross vehicle weight in excess of 10,000 pounds are exempted from the requirements to pay the token fee and display the associated distinguishing license plate provided for in Transportation Code, §502.255. An annual permit is required for the power unit only. For vehicles registered in combination, the combined gross weight may not be less than 18,000 pounds.
43 Tex. Admin. Code § 217.40