Tex. Alco. Bev. Code § 201.71

Unless the liquor is exempt from tax or payment has been or is to be made by a permittee in accordance with the provisions of Subchapter A or B of this chapter, the tax levied under Subchapter A or B shall be paid by affixing a stamp or stamps on each bottle or container of liquor. The stamp shall be affixed in strict accordance with the commission's rules and regulations.