N.H. Code Admin. R. Saf-Mec 301.13
“Master plumber” means “master plumber” as defined in RSA 153:27, XII, namely, "any person, firm, corporation, or limited liability company that, as a business, hires or employs a person or persons to do plumbing work, or, without hiring any person, does that work as a principal business or as auxiliary to a principal business for its own account."
Source. #10648, EMERGENCY RULE, eff 7-25-14, EXPIRES: 1-21-15; ss by #10761, INTERIM, eff 1-21-15, EXPIRES: 7-20-15; ss by #10847, eff 7-1-15 (from Saf-Mec 303.13)