State Tax Return Filing: Residency, Part-Year Income, Free Filing
Your federal return isn't the whole story — here's when you also need a state return, and how to handle a mid-year move between states.
In short: Your federal return with the IRS is completely separate from your state return. Only nine states currently charge no individual income tax; the rest each require their own return with residency rules that can differ from federal ones. If you moved between two states in the same year, or work in one state while living in another, you may need more than one state return, with your income split by period and geographic source.
Why is a state return separate from the federal one?
The IRS is a federal agency that collects tax nationwide, while each state runs its own tax agency (often called a Department of Revenue or Department of Taxation) under its own law. Filing your federal return (Form 1040 or 1040-NR) does not cover any obligation you may owe a state. The general rule: if you have income sourced within a state that taxes income, or you're a resident of one, you likely owe that state a separate return, regardless of your federal status (resident or nonresident alien for federal purposes).
The definition of "who is a resident" for tax purposes varies by state and doesn't always match the federal definition. Some states count actual days present (often around 183 days as a common threshold, though the exact number and details vary), while others focus on where your permanent home, or "domicile," is regardless of day count. Don't assume the federal and state residency definitions line up.
The nine states with no income tax
Nine states currently charge no individual income tax on wages: Alaska, Florida, Nevada, New Hampshire, South Dakota, Tennessee, Texas, Washington, and Wyoming. That doesn't mean no taxes at all — these states typically make up for it with higher sales or property taxes, and some (like Washington) tax capital gains for certain high earners even though they don't tax regular wages.
| Situation | What it usually means |
|---|---|
| You live and work in one of the nine no-tax states | Usually no state income tax return |
| You live in a no-tax state but work remotely or in-person for an employer in a taxing state | You may need a nonresident return in the work state |
| You live in a state that taxes income | A resident return usually covers your total income, sometimes even from out-of-state sources, with a credit to avoid double taxation |
See our full breakdown of every state's tax rules in the state income tax by state guide.
Moved between two states in the same year: how is income split?
If you moved your residence from one state to another mid-year, and both states tax income, you typically file a "part-year resident" return in each. The basic process:
- Pin down the actual date your permanent home changed — not just the date you signed a new lease or registered a driver's license.
- Total your earned income by state, matched to the time period and geographic source (wages from an employer in the first state before the move, then from the second state after).
- Complete each state's "part-year resident" form; some ask you to allocate income by day count, others by actual date-based splitting.
- Check for a tax credit either state offers to avoid double-taxing the same income.
Note: A physical move alone doesn't always prove a change in tax residency if you kept property, a driver's license, or voter registration in the old state. Some states, especially higher-tax ones, actively scrutinize these details if they doubt the real move date.
Working in one state, living in another
This is common if you live near a state border or work under contract in a different state. The general rule:
- A nonresident return in your work state covering only income earned there.
- A resident return in your home state covering your total income from everywhere.
- A tax credit in your home state usually offsets what you paid the work state, to avoid paying tax twice on the same income, though the calculation method differs by state.
Some pairs of neighboring states have a "reciprocity agreement" that lets you work in one and file only in your home state without a nonresident return, so check your specific pair of states by name, since these agreements don't exist between every pair.
Free filing options
A number of IRS Free File partners include a free state return in the same package that covers your federal return, depending on your income and state, but not all partners include it. The practical steps:
- Open the official IRS Free File page and check which partners are available for your income level.
- Look specifically for "state return included" or equivalent wording before you start — some partners only give the federal return for free and charge for the state one.
- Check your state tax agency's own site directly; some states run their own free e-filing system independent of IRS Free File.
State filing deadlines
In most states, the deadline matches the usual federal one (mid-April), but some set a different date or grant an automatic extension tied to your federal extension without a separate request. Don't assume it always matches; check your specific state tax agency each year, since some states adjust deadlines in particular years.
Example: an engineer who moved from Texas to California
Say Youssef worked the first 5 months of the year in Texas (no income tax), then moved for a new job to California (one of the highest state income tax rates) in month six. On his federal return, none of this matters — he reports his total income from both in one return to the IRS. At the state level, though, Youssef files no state return at all for his Texas months, since Texas doesn't tax income to begin with. He files a "part-year resident" return in California covering only the income he earned after he actually moved and became a resident there, not the first five months. This works in his favor: because half his year was in a no-tax state, that income never becomes subject to California tax, as long as he clearly documents his move date (new lease, updated driver's license, voter registration) so California doesn't treat the whole year as residency there.
The reverse holds too: someone who moved from California to Texas mid-year files a California part-year resident return covering only income earned during actual California residency, with no return owed for the later Texas months. A common mistake is assuming California will tax the whole year; that's not correct if the person can document the real move date with paperwork.
Remote workers for an out-of-state employer
Many newcomers work remotely for a company headquartered in a different state than where they live. The general rule is that state tax usually follows where you physically are when you do the work, not where the company is based — unless there are frequent visits to the employer's state, or a state applies a "convenience of the employer" rule, as a few states like New York do, which can tax remote income even from someone working out of state in certain circumstances. Don't assume the general rule automatically applies here; check the specific rule for your employer's headquarters state if it's one known for this exceptional rule.
Common mistakes
- Assuming the federal return is enough and forgetting a state return entirely.
- Thinking the physical move alone ends your old tax residency without updating supporting documents (driver's license, voter registration, primary address).
- Not claiming the credit for tax paid to another state, so you end up paying tax twice on the same income.
- Confusing federal residency rules with state residency rules, which sometimes differ.
- Assuming a reciprocity agreement exists between two states without checking by name.
What to do next
- Pin down which state(s) you lived and worked in this year.
- Check each state's specific rules in the state income tax by state guide.
- If you moved this year, gather documents for a part-year resident return in both states if both tax income, and see our moving between states guide.
- Start with your federal return first using our first tax return guide, since most state returns build on those numbers.
Frequently asked questions
Does every state charge income tax?
No. Nine states currently charge no individual income tax: Alaska, Florida, Nevada, New Hampshire, South Dakota, Tennessee, Texas, Washington, and Wyoming. The rest each set their own rates and rules.
I moved between states mid-year — how many returns do I file?
Usually a part-year resident return for each state that taxes income, with your income split by the period and geographic source of each part.
I work in one state but live in another — what do I file?
Typically a nonresident return in your work state for income earned there, and a resident return in your home state for your total income, often with a credit in your home state to avoid double taxation. Check both specific states — some have reciprocity agreements.
Is free state filing available?
Some IRS Free File partners include a free state return in the same package depending on income and state, but not all do. Check the IRS Free File page and your specific state tax agency's site.
Is the state deadline the same as the federal one?
In most states, yes, but some set a different date or grant an automatic extension tied to a federal extension. Check your specific state tax agency rather than assuming April 15 everywhere.
I'm a federal nonresident alien (filing 1040-NR) — do I need a state return too?
You might. State residency rules are separate from federal rules, and if you have income sourced in a state that taxes income, you usually owe a separate state return regardless of your federal status.
Official sources we reviewed
- IRS — Free File: Do Your Federal Taxes for Free ↗
- Consumer Financial Protection Bureau — Filing taxes ↗
- IRS — Taxation of Nonresident Aliens ↗