Contractors are generally the final consumer of the materials that they purchase which are used in performing their services, and they must pay the applicable sales and use tax for said purchases. However, Conn. Agencies Regs. §12-426-18(b)(1)(2) states situations whereby contractors are considered to operate as retailers and may issue resale certificates for parts that they resell to their customers. In this situation, the contractor/retailer must apply tax to the total sales price billed to his customers for the parts.
Based on the information presented in your letter, your client appears to be conducting business as a retailer provided he is registered with this Department as a retailer of plumbing supplies, materials and/or parts.
December 7, 1989