Section 3. (a) Except as provided in paragraph (c), reimbursement for the tax hereby imposed 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, or an amount equal as nearly as possible or practicable to the average equivalent thereof; 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.

(b) Any purchaser who operates a business and who acquires tangible personal property or services may apply to the commissioner for a direct payment permit. The commissioner, in his discretion, may issue a direct payment permit to the purchaser. A direct payment permit shall provide that no vendor making a sale to the permit holder shall be required to collect the sales or use tax otherwise payable on such sale and that the permit holder shall report, on such form as the commissioner shall designate, and pay directly to the commissioner the sales or use tax due on any tangible personal property or services acquired by him.

The use of a direct payment permit shall not affect the amount of sale or use tax due with regard to any transaction, but liability for payment of the sales or use tax shall be placed on the purchaser rather than on the vendor.

A direct payment permit shall be in a form prescribed by the commissioner and shall bear an identifying registration number, an issue date, an expiration date and a list of the types of transactions for which the permit cannot be used. The use of a direct payment permit shall be subject to such conditions as the commissioner shall determine to be appropriate, but such use shall not include purchases of motor vehicles or purchases of a personal nature. The commissioner shall issue regulations on the use of direct payment permits and such regulations may include, but shall not be limited to, requirements for the permit holder's duties to vendors, posting bond, monthly reporting and payment of tax, recordkeeping and periodic renewal of the direct payment permit.

The direct payment permit may be revoked by the commissioner at any time with the provision of 30 days' written notice and shall be revoked without notice if the commissioner determines that the collection of any tax due from the permit holder is in jeopardy. Any person whose direct payment permit is either voluntarily forfeited or canceled by action of the commissioner shall return the permit to the commissioner and immediately notify all vendors from whom purchases of taxable items are made advising them that such person's direct payment permit is no longer valid.

A person who fails to give notification shall be fined $1,000 per vendor to which notification was required to have been given. A direct payment permit shall not be transferable and the use of a direct payment permit shall not be assigned to a third party. The acceptance in good faith by any vendor of a certificate from a permit holder to the effect that he is in possession of a valid direct payment permit shall relieve such vendor of any obligation to collect the tax from the permit holder. Such certificate shall be in a form prescribed by the commissioner and shall be signed by and bear the name and address and registration number of the permit holder, as well as the permit's issue date, expiration date and list of prohibited transactions.

(c) The excise imposed by section two upon sales at retail of motor vehicles or trailers shall be paid by the purchaser to the registrar of motor vehicles in the manner prescribed by the commissioner. The vendor thereof shall not add the tax to the sales price and shall not collect the tax from the purchaser. The vendor thereof shall, however, furnish to the purchaser, the registrar and the commissioner a sworn statement of the sale upon a form prescribed by the commissioner, with the approval of the commission, giving such information as the commissioner may require for the determination of such tax. On any form prescribed by the commissioner under this section, the purchaser shall be required to identify the place of his principal residence under the pains and penalties of perjury. For the purpose of this paragraph, the term ''motor vehicle'' means any self-propelled vehicle designed for use and used primarily upon the highways.