T/P from NYS is now working and living in Canada for a 2–3-year period. His employer, the FBI, is withholding Federal and NYS income tax. He does not have a residence in NYS, just a PO Box for mail. Is he subject to NYS income tax, or can he file as a Non-Resident and get a full refund of the NYS taxes withheld?
His wife is in the same position, but she is using her mothers NJ address for mail.