If you earned income in a state where you don’t live, both that state and your home state may tax the same dollars. The credit for taxes paid to another state is your home state’s fix for that overlap: it reduces your home-state tax by the amount you paid the other state on the shared income, but only up to what your home state itself would have charged on that income. If the other state’s rate is higher, you absorb the difference.
When the Credit Applies
Two things have to be true. You must be filing as a resident (usually full-year) of the state that would grant the credit, and the income in question must have been taxed by both your home state and the other state. If only one state taxed it, there’s no double taxation to fix.
The other state is wherever you earned the income and filed a non-resident return. Common triggers: wages from commuting across a state line, business income from services performed in another state, rental income from out-of-state property, and capital gains tied to real estate or business interests located there. The income has to actually appear on your non-resident return and produce a tax liability before your home state will credit anything.
One boundary worth naming. Nine states levy no individual income tax: Alaska, Florida, Nevada, New Hampshire, South Dakota, Tennessee, Texas, Washington, and Wyoming. If your out-of-state income was earned in one of them, there’s no non-resident tax, and no credit question to work through. Non-resident filing thresholds also vary from state to state; if you fall below the threshold where you worked, you won’t owe tax there and won’t have anything to credit at home.
Use Your Actual Liability, Not Your Withholding
This is where most claims go wrong. The credit is based on the final tax you owe on the non-resident return, not what your employer withheld during the year. Those two numbers are often different. If $3,000 was withheld for the non-resident state but your actual liability comes out to $2,200, your credit is $2,200. Using the withholding figure overstates the credit, and your home state will catch it.
The flip side matters too. If too little was withheld and you had to send an additional payment with the non-resident return, your credit should reflect the full liability you paid, not just the withholding. Either way, finish the non-resident return before touching the home-state return.
How the Credit Is Calculated
Your home state caps the credit at the lesser of two numbers:
- The tax you actually paid the other state on the income taxed by both.
- The tax your home state would have charged on that same income.
The second figure comes from a fraction. The numerator is the income taxed by both states. The denominator is your total adjusted gross income on your home-state return. Multiply that fraction by your total home-state tax, and you have the ceiling.
A worked example. You earned $120,000 total, $30,000 of which was sourced to the non-resident state. Your home-state tax on the full $120,000 is $6,000. You paid $2,700 to the non-resident state on the $30,000. The ratio is $30,000 รท $120,000, or 25%. Twenty-five percent of $6,000 is $1,500, and that’s the most your home state will credit. Even though you paid $2,700 to the other state, your credit stops at $1,500. The remaining $1,200 is a permanent cost; most states do not let you carry the unused portion to a future year.
The cap bites hardest when the non-resident state’s rate is meaningfully higher than your home state’s.
Filing Order and Documentation
Complete the non-resident return first. Its final tax liability feeds directly into the credit on your home-state return, so there is no way to work the two in parallel without guessing.
Your home-state return will include a dedicated schedule, typically titled something like “Credit for Taxes Paid to Other States” or “Other State Tax Credit.” Form names and numbers differ, but every state with an income tax and a resident credit has one. On that schedule you’ll enter the other state’s name, the income taxed by both, and the tax actually paid to the non-resident state.
Most states want a complete copy of the non-resident return attached, including schedules and W-2s showing income allocated to that state. Some also want proof of payment: a bank record, a payment confirmation from the other state’s tax agency, or similar documentation. E-filing software usually handles the attachment, but keep your own copies regardless.
If you owed tax to more than one non-resident state, calculate the credit separately for each. Each state gets its own line and its own lesser-of comparison. The credits don’t pool.
Reciprocal Agreements Between States
About 16 states participate in reciprocal tax agreements with at least one neighboring state. Under a reciprocal agreement, the non-resident state simply doesn’t tax your wages when you live in the partner state. You file an exemption form with your employer, the non-resident state doesn’t withhold, and no non-resident return is required for that wage income. Nothing to credit, because the double taxation never happens.
Reciprocal agreements cover wages and salary only. Business income, rental income, and capital gains sourced to the other state are not protected, and you’d handle those through a non-resident return and the standard credit.
If your employer withheld for the non-resident state anyway, usually because you never filed the exemption form, you need to file a non-resident return in that state to get the withholding back. You can’t claim a home-state credit for withholding that shouldn’t have happened in the first place.
Remote Workers and the Convenience of the Employer Rule
About eight states enforce some version of a “convenience of the employer” rule. If you work remotely from your home state for an employer based in one of those states, the employer’s state may tax your wages as if you performed the work there, on the theory that you’re remote for your own convenience rather than because the employer requires it.
That produces real double taxation that the standard credit only partly solves. Your home state taxes you because you’re a resident. The employer’s state taxes you under the convenience rule. You can claim the credit, but if the employer’s state has the higher rate, you eat the gap. If both states push to tax the income at full freight, you may need to request an adjustment or exclusion from the employer’s state directly. These situations are complicated enough that professional help is usually worth paying for.
Pass-Through Entity Income
If you’re a partner in a partnership or shareholder in an S corporation operating in multiple states, the K-1 income reported to you may already have had state tax paid at the entity level. Many states let or require the entity to file a composite return and pay tax on behalf of non-resident owners.
Whether those entity-level payments qualify for the credit on your personal home-state return depends on your home state. Some treat them as if you paid the tax yourself; others draw a line between tax paid by the entity and tax paid by the individual, which can shrink or complicate the credit. The K-1 or a supplemental statement should tell you how much state tax was paid on your behalf.
A related wrinkle: many states have adopted pass-through entity taxes, which generate an offsetting credit on the owner’s individual state return. When that credit sits alongside a credit for taxes paid to another state, the interaction can get tangled, and the rules vary by state. Getting it wrong can mean either forfeiting money you were owed or claiming a credit you can’t support.
Local Taxes Usually Don’t Count
The credit generally covers only income tax paid to another state government. City and county income taxes in the non-resident state typically don’t qualify. A few states do allow credits for local taxes paid elsewhere, but that’s the exception. Check your home state’s credit instructions on this specifically, because a local tax of 1% to 3% that no one credits adds up quickly.
If the Other State Later Adjusts Your Return
If the non-resident state changes your tax liability later, through an audit, an amended return, or a correction, your home-state credit has to change too. A refund from the non-resident state means you overclaimed the credit at home and probably owe some of it back. Most states expect an amended return to fix this. States share information, and the mismatch will surface eventually.
Keep your non-resident returns, payment confirmations, and supporting documents for at least three years from the filing date, which lines up with the general federal record-retention period.1Internal Revenue Service. How Long Should I Keep Records? Some state audit windows run four or five years, so holding records that long is safer. If an adjustment lands two years after filing, you’ll need the original return to recalculate the credit on the amended home-state return.2Internal Revenue Service. Topic No. 305, Recordkeeping