Why this matters

If you lived, worked, or earned income in more than one state during a tax year, you will usually need to file a state return in each state with a tax claim on your income. That often means a resident return in the state where you live, and nonresident or part‑year resident returns in the other states where you earned money. State rules vary, so the specific forms and credits depend on each state’s tax agency (see your state’s revenue department and IRS general guidance at https://www.irs.gov).

Core forms and return types you’re likely to see

  • Resident individual return — filed by people who are domiciled or meet residency tests in the state (examples: New York IT‑201, California Form 540).
  • Part‑year resident return — used when you moved between states during the year; you report income for the period you were a resident.
  • Nonresident return — for income sourced to a state where you worked but did not live (examples: New Jersey NJ‑1040 Nonresident schedules).
  • Withholding and wage forms — W‑2s and 1099s show state wages and withheld taxes; employers may report multiple state wages on a single W‑2.
  • Schedules for allocating income — many states require a schedule to allocate wages, business income, rental income, or capital gains to the state where they were earned.

Typical workflow (practical steps)

  1. Gather documents: W‑2s, all 1099s, pay stubs that show state withholding, moving records, and dates you were physically present in each state.
  2. Determine residency status for each state: resident, part‑year resident, or nonresident. States use tests such as domicile, days‑present, or statutory residency; see our guide on residency tests for details (https://finhelp.io/glossary/state-residency-tests-explained-how-they-impact-your-tax-return/).
  3. Prepare federal return first — some state calculations start with federal AGI. Use federal numbers to allocate income to states.
  4. File resident return in your home state and nonresident/part‑year returns in other states as required. Claim a credit on your resident return for taxes paid to other states if the state allows it.
  5. Keep documentation for allocations and any reciprocity or withholding exemptions.

Credits, reciprocity, and double taxation

Many states provide a credit against resident tax for income taxes paid to another state to avoid double taxation. Some neighboring states have reciprocity agreements that exempt commuter wages from the nonresident state (common examples are PA/NJ, MD/DC). Check state guidance and our reciprocity primer for specifics: https://finhelp.io/glossary/state-income-tax-reciprocity-what-it-means-for-commuters/ and https://finhelp.io/glossary/dealing-with-multiple-state-returns-after-a-midyear-move/.

Common mistakes to avoid

  • Not filing a nonresident return when you had state‑sourced income (commuting, rental property, business activity).
  • Failing to allocate income correctly; blanket residency assumptions can trigger audits.
  • Overlooking reciprocity agreements or required withholding exemption forms your employer must have on file.
  • Assuming no filing requirement because you pay federal estimated taxes — state requirements differ.

When to contact a pro

If you have multiple income sources across many states, rental or business income in other jurisdictions, or complex residency facts (temporary assignments, remote work for an out‑of‑state employer), consult a tax professional. In my practice I’ve found that early documentation of move dates and work locations reduces filing time and audit risk.

Helpful links and authoritative sources

Quick examples

  • Moved midyear from Florida (no state income tax) to Virginia: file a part‑year resident return in Virginia for income earned after your move; Florida requires no income return.
  • Live in New York and work part‑time in New Jersey: file a resident NY IT‑201 and a NJ nonresident return; claim credit on NY for taxes paid to NJ if allowed.

Disclaimer

This article provides educational information and does not replace personalized tax advice. State rules change and facts matter; consult your state revenue department or a licensed tax professional for guidance tailored to your situation.