Mass. Gen. Laws ch. 64H, § 30A
(c) Where a person dealing with a nonresident contractor fails to comply with subsection (b), he is personally liable for payment of the tax imposed by this chapter relative to tangible personal property consumed or used pursuant to or in the carrying out of the contract.
As used in this section ''contractor'' shall mean any person engaged in the construction, reconstruction, alteration, remodeling or repair of real property.