Residence versus work location
Your residence state taxes you on all your income. A state where you physically perform work can also tax that work-location income. Most states give a credit on your residence return for tax paid elsewhere, so you usually do not get double-taxed on the same dollar. You do file in both.
Reciprocity agreements
Some state pairs let you pay only the residence state. Common examples: Pennsylvania with New Jersey (limited), Illinois with Indiana, Maryland with Virginia, Wisconsin with Illinois, Michigan with Indiana, Kentucky with Indiana. To use reciprocity you file an exemption form with your employer so they only withhold for your residence state.
Convenience-of-employer rule
New York, Connecticut, Delaware, Nebraska and Pennsylvania (in some scenarios) apply this rule. If you work remotely from another state for the employer's convenience rather than your own necessity, the employer's state still taxes you. New York is the most aggressive about it. Even non-residents working remotely for a NY employer can owe NY tax.
What to do
- Pin down your residence state. Where you spend most days, where you vote, your driver's license.
- Track which days you worked in which state if you cross state lines.
- File a state return in every state where you owe.
- Claim the credit for tax paid to another state on your residence return.
- Talk to a CPA. Multi-state remote work is one of the trickier areas of the tax code.