The following acts are prohibited by contractors or subcontractors:

1. (1) operating without a certificate of registration issued by the director;
2. (2) abandoning or failing to perform, without justification, any contract or project engaged in or undertaken by a registered contractor or subcontractor, or deviating from or disregarding plans or specifications in any material respect without the consent of the owner;
3. (3) failing to credit to the owner any payment they have made to the contractor or his salesperson in connection with a residential contracting transaction;
4. (4) making any material misrepresentation in the procurement of a contract or making any false promise of a character likely to influence, persuade or induce the procurement of a contract;
5. (5) knowingly contracting beyond the scope of the registration as a contractor or subcontractor;
6. (6) acting directly, regardless of the receipt or the expectation of receipt of compensation or gain from the mortgage lender, in connection with a residential contracting transaction by preparing, offering or negotiating or attempting to or agreeing to prepare, arrange, offer or negotiate a mortgage loan on behalf of a mortgage lender;
7. (7) acting as a mortgage broker or agent for any mortgage lender;
8. (8) publishing, directly or indirectly, any advertisement relating to home construction or home improvements which does not contain the contractor's or subcontractor's certificate of registration number or which does contain an assertion, representation or statement of fact which is false, deceptive, or misleading;
9. (9) advertising in any manner that a registrant is registered under this chapter unless the advertisement includes an accurate reference to the contractor's or subcontractor's certificate of registration;
10. (10) violation of the building laws of the commonwealth or of any political subdivision thereof;
11. (11) misrepresenting a material fact by an applicant in obtaining a certificate of registration;
12. (12) failing to notify the director of any change of trade name or address as required by section thirteen;
13. (13) conducting a residential contracting business in any name other than the one in which the contractor or subcontractor is registered;
14. (14) failing to pay for materials or services rendered in connection with his operating as a contractor or subcontractor where he has received sufficient funds as payment for the particular construction work, project or operation for which the services or materials were rendered or purchased;
15. (15) failing to comply with any order, demand or requirement lawfully made by the administrator or fund administrator under and within the authority of this chapter;
16. (16) demanding or receiving payment in violation of clause (6) of paragraph (a) of section two;
17. (17) engaging in gross fraud or cheat pursuant to section 76 of chapter 266;
18. (18) having a license, certificate, registration or authority issued by another state or territory of the United States, the District of Columbia or a foreign state or nation with authority to issue such a license, certificate, registration or authority revoked, cancelled, suspended, not renewed or otherwise acted against, or if the holder has been disciplined, if the basis for the action would constitute a basis for disciplinary action in the commonwealth;
19. (19) failing to repay the fund in full, including the appropriate amount of annual interest, for any amount paid from the fund because of the contractor's or subcontractor's conduct; or

20. (20) violating any other provision of this chapter.

    Violations of this section shall subject the violator to the administrative sanctions of section eighteen and to criminal prosecution as prescribed in section nineteen.

    Violations of any of the provisions of this chapter shall constitute an unfair or deceptive act under the provisions of chapter ninety-three A.

    For purposes of this section, the conduct of a contractor or subcontractor shall be deemed to include the conduct of their agents, employees, salespersons or subcontractors, whether or not an express relationship exists, if the work or activities is within the scope of the contract and not for additional work beyond the contract undertaken by separate agreement with the owner.