Under M.G.L. c. 62, § 5A(a), income of a non-resident derived from a trade or business, including any employment, carried on in the commonwealth is sourced to Massachusetts. Pursuant to this rule, all compensation received for personal services performed by a non-resident who, immediately prior to the Massachusetts COVID-19 state of emergency, was an employee engaged in performing such services in Massachusetts, and who during such emergency is performing such services from a location outside Massachusetts due solely to the Massachusetts COVID-19 state of emergency, will continue to be treated as Massachusetts source income subject to personal income tax under M.G.L. c. 62, § 5A and personal income tax withholding pursuant to M.G.L. c. 62B, § 2.