@seafox69 -
<<I am not required to work at home in NH, I elect to>>
I truly believe this is why you are taxed by MA - you are working in NH for your convenience and are otherwise required by your employer to be in MA each working day
<<How would we identify whether the employer or employee specified the arrangement>>
this is up to the Payroll and HR department to control. I used to work for a big company (> 100,000 employees) and 'work location' was always the link to which state's was used for withholding and reported taxable income
<<why would it matter for tax purposes? >>
because high tax states need to protect their income tax stream in a tele-commuting world and differentiate between who is working in a low income tax state (e.g. NH) because their employer required it or because it was convenient for the employee. Hard to argue in court for the former; easier to argue in court for the latter.
What would occur if you asked your employer to change the relationship?, meaning the employer agreed you are assigned to a NH location and expected to work from there (just create the code in the computer - the physical location already exists: your home)
and why would it matter for tax purposes?
