My husband works and live (APT) in Idaho for 6 years. I used to work and live in Idaho too but for a year I moved to WA, (work and live in an APT also). We have a college student dependent. My questions, what's the best way to file tax return for federal? How about state tax? Since there's no income tax in WA and ID does. If we file jointly, then I have to pay state tax in ID? We don't have a house there and I have been there for a visit. Thank you.

With respect to federal income tax, what state you are in really doesn't matter, except that you may be able to deduct state income taxes paid.

If you work in Washington, and have made no income in Idaho, you would not pay income tax to Idaho. Your husband would, however, so if you file jointly you would report Idaho income on your state return (and of course report both of your incomes on your federal return). You might want to consult a tax preparer in Idaho, or use tax preparation software to be sure you do the details right.