If you earn 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 bill by the amount you paid to the other state on the same income, up to a cap. The cap is the part that surprises people. Your home state will not credit you more than it would have charged on that income itself, so if the other state’s rate is higher, you absorb the difference.
Who Qualifies
Two conditions have to be met. You must be filing as a resident (usually a full-year resident) of the state granting the credit, and the income you’re claiming the credit on must have been taxed by both your home state and the other state. If only one state taxed the income, there is no double taxation and nothing to credit.
The other state is where you earned the income and filed a non-resident return. Common triggers include wages earned while commuting across a state border, business income from services performed in another state, rental income from property located there, and capital gains tied to real estate or business interests in that state. The income has to actually appear on your non-resident return and generate a tax liability there before your home state will consider it.
One boundary worth stating up front: nine states levy no individual income tax, so income earned in Alaska, Florida, Nevada, New Hampshire, South Dakota, Tennessee, Texas, Washington, or Wyoming generates no non-resident tax to credit. And each state that does tax income sets its own non-resident filing threshold, which can range from a single dollar of income to figures above $15,000. If your income in the other state falls below its threshold, no tax is owed there and no credit arises.
File the Non-Resident Return First
The sequence is not optional. Complete the non-resident state’s return before you touch your home-state return. The final tax liability from that non-resident return is the number that feeds into the credit calculation at home. Filing your home-state return first means guessing at the credit, and the guess will be wrong often enough to cause a notice.
Use Your Actual Tax, Not Your Withholding
This is where most claims go sideways. The credit is based on the tax you actually owe on your non-resident return, not the amount your employer withheld for that state during the year. Those two numbers are often different. If your employer withheld $3,000 for the non-resident state but your actual liability turned out to be $2,200, your credit is based on $2,200. Using the withholding figure inflates the credit, and your home state will catch it.
The reverse also happens. If too little was withheld and you owed an additional payment when you filed the non-resident return, the credit should reflect the full liability you paid, not just what came out of your paychecks.
How the Credit Is Calculated
Your home state limits the credit to the lesser of two amounts:
- the tax you actually paid to the other state on the income that was taxed by both jurisdictions, or
- 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 liability, and you have the maximum credit your home state will allow.
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, and you paid $2,700 to the non-resident state on the $30,000. The ratio is 25% ($30,000 รท $120,000). That means 25% of your $6,000 home-state tax, or $1,500, is the ceiling. Even though you paid $2,700 to the other state, your credit stops at $1,500. The remaining $1,200 is gone. You have effectively paid the higher rate to the non-resident state with no offset for the difference.
This cap bites hardest when the non-resident state’s rate is meaningfully higher than your home state’s. Most states also do not let you carry the unused portion forward, so the excess is a permanent cost, not a timing issue.
Documentation on the Home-State Return
Your home-state return will include a dedicated schedule for the credit, often named something like “Credit for Taxes Paid to Other States” or “Other State Tax Credit.” The exact form and number vary, but every state with an income tax and a resident credit has one. On that schedule you enter the non-resident state’s name, the income taxed by both states, and the actual tax paid to the non-resident state.
Most states require you to attach a complete copy of your non-resident return, including all schedules and W-2s showing income allocated to that state. Some also want proof of payment, whether a bank record or a payment confirmation from the other state’s tax agency. E-filing software usually handles the attachment, but keep the documents in your own records either way.
If you owed tax to more than one non-resident state, calculate the credit separately for each. Each state gets its own line on the credit schedule with its own lesser-of comparison. The credits don’t pool.
Reciprocal Agreements
About 16 states participate in reciprocal tax agreements with at least one neighboring state. Under these agreements, the non-resident state simply doesn’t tax the wages of a resident of the partner state. You file an exemption form with your employer, the non-resident state doesn’t withhold, and you never file a non-resident return for that wage income. No non-resident return, no credit to claim, because the double-taxation problem never arises.
Reciprocal agreements cover only wages and salary. Business income, rental income, and capital gains sourced to the other state fall outside the agreement, so you still file a non-resident return for those and claim the credit on your home-state return in the usual way.
One common mistake: if your employer withheld for the non-resident state despite a reciprocal agreement (usually because the exemption form was never filed), you have to file a non-resident return in that state to recover the withholding as a refund. You cannot use the withholding as the basis for a credit on your home-state return.
Remote Work and the Convenience 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 still tax your wages as if you performed the work there. The rule applies when you’re working remotely for your own convenience rather than because the employer requires it.
This produces genuine double taxation that the standard credit only partially solves. Your home state taxes the income because you’re a resident. The employer’s state taxes it under the convenience rule. You can claim the credit at home, but if the employer’s state has a higher rate, you absorb the difference. If both states claim the right to tax the same income at full rates, you may need to request an adjustment or exclusion directly from the employer’s state. These situations are complicated enough that professional help is worth the cost.
Pass-Through Entity Income
If you’re a partner in a partnership or a shareholder in an S corporation operating in multiple states, the K-1 income reported to you may already have had state taxes paid on it at the entity level. Many states allow or require the entity to file a composite return and pay tax on behalf of its non-resident owners.
Whether those entity-level payments qualify for the credit on your personal home-state return depends on your home state’s rules. Some treat them as if you paid the tax personally, making the credit straightforward. Others distinguish between taxes paid by the entity and taxes paid by the individual, which can reduce or complicate the credit. The K-1 or a supplemental statement should show how much state tax was paid on your behalf, and that’s the figure to work with.
Local Taxes Usually Don’t Count
The credit generally applies only to income taxes paid to another state government. Taxes paid to a city, county, or other local jurisdiction within the non-resident state typically don’t qualify. A handful of states do allow credits for local taxes paid elsewhere, but that’s the exception. Check your home state’s credit instructions specifically on this point, because a local income tax of 1% to 3% that can’t be credited anywhere adds up fast.
If the Other State Adjusts Your Return Later
If the non-resident state later changes your tax liability through an audit, an amended return, or a correction, your home-state credit needs to change too. A refund from the non-resident state means you overclaimed the credit and probably owe the difference back to your home state. Most states expect you to file an amended return to fix it. States share information, and the mismatch surfaces eventually.
Keep your non-resident returns, payment confirmations, and supporting documents for at least three years from the filing date, which aligns with the general federal record-retention period.1Internal Revenue Service. How Long Should I Keep Records? Some states have longer audit windows that stretch to four or five years, so holding records for at least that long is safer. If a refund or adjustment arrives two years after filing, you’ll need the original return to recalculate the credit on your amended home-state return.2Internal Revenue Service. Topic No. 305, Recordkeeping