"I want to know if I should be paying mass taxes on hours worked in NH?"
No, you should not.
Since you are a non-resident of MA, you are subject to MA income tax only on income you earn from work you actually (physically) perform within Massachusetts.
If you did carry on a part of your work within Massachusetts, then you need to pro-rate your income in order to determine the portion taxable by MA. You can use any common-sense method to do the pro-rate. Example: Total workdays for the year = 200; MA workdays = 20; then 20/200 or 10% of your income is taxable by MA.
If the amount of MA tax withheld from your pay exceeds your MA taxes due, then MA will send you a refund.
**Answers are correct to the best of my ability but do not constitute tax or legal advice.
