Mass. Gen. Laws ch. 64L, § 4: Reimbursement to vendor by purchaser

Section 4. Reimbursement for the tax imposed by this chapter shall be paid by the purchaser to the vendor, and each vendor in the commonwealth shall add to the sales price and shall collect from the purchaser the full amount of the tax imposed by this chapter and such tax shall be a debt from the purchaser to the vendor, when so added to the sales price, and shall be recoverable at law in the same manner as other debts.