The state tax information on your W-2 lives in Boxes 15 through 20 at the bottom of the form, with Box 14 handling other payroll items like disability insurance and paid family leave. Box 15 identifies the state and your employer’s state tax ID. Box 16 reports the wages your state considers taxable. Box 17 shows how much state income tax was withheld from your paychecks. Boxes 18 through 20 do the same for city or county taxes when a local jurisdiction imposes them. If you worked only in one of the eight states with no personal income tax, those boxes will be blank.
What Each State Box Reports
Box 15 shows a two-letter state abbreviation and your employer’s state tax identification number, which is assigned by that state’s revenue department rather than the IRS. If your employer withheld taxes for more than one state during the year, Box 15 will carry multiple entries, each on its own line.1Internal Revenue Service. 2026 General Instructions for Forms W-2 and W-3
Box 16 is your total wages taxable by that state. Box 17 is the state income tax your employer actually withheld across the year. When you file your state return, the Box 17 amount gets compared against your real tax liability. If withholding exceeded what you owe, you get a refund. If it fell short, you pay the difference.1Internal Revenue Service. 2026 General Instructions for Forms W-2 and W-3
Why State Wages Often Don’t Match Federal Wages
Box 16 (state wages) frequently sits close to Box 1 (federal wages), but the two are not required to match. States write their own rules about what counts as taxable income. A common cause of the gap: some states treat 401(k) contributions as taxable even though the federal government does not. If your state does not allow that deduction, Box 16 comes in higher than Box 1. Pre-tax transit benefits and working in more than one state during the year can produce a similar difference. A mismatch is usually not an error. It reflects how your state defines taxable wages.
Local Taxes in Boxes 18 Through 20
If you work in a city or county that imposes an income tax, Boxes 18 through 20 will be filled in. Box 18 shows wages subject to the local tax, Box 19 shows the local tax withheld, and Box 20 identifies the locality by name or code.1Internal Revenue Service. 2026 General Instructions for Forms W-2 and W-3
Local income taxes are more common than many people realize. New York, Philadelphia, and Detroit all levy their own taxes on top of state and federal obligations. If you moved mid-year or worked in more than one taxing locality, you may see multiple entries in these boxes, just as you can for multiple states in Boxes 15 through 17.
What Box 14 Covers
Box 14 is a catch-all for deductions and contributions that don’t fit into other boxes. Each item should carry a label so you know what it represents. Typical entries include state disability insurance premiums, state unemployment insurance contributions, union dues, and employer-sponsored health insurance premiums.2Internal Revenue Service. General Instructions for Forms W-2 and W-3 (2026) – Box 14a Other
Paid family and medical leave contributions are showing up in Box 14 more often as more states create these programs. These assessments fund wage replacement for workers who need time off for a serious health condition or to care for a family member. They come out of your paycheck alongside income tax withholding, but they are legally separate from income taxes and typically cannot be deducted on your federal return.2Internal Revenue Service. General Instructions for Forms W-2 and W-3 (2026) – Box 14a Other
Employers have discretion over how they label Box 14 items, so the same deduction can appear under different names on W-2s from different employers. If a label is unfamiliar, check with your payroll department before assuming it affects your return.
How State Withholding Is Calculated
When you start a job, most states require you to complete a state-specific withholding certificate in addition to the federal W-4. The form asks for your filing status, the number of allowances you’re claiming, and sometimes an extra dollar amount you want withheld. Your employer feeds those selections into state-provided tax tables to calculate how much to take out of each paycheck.3EDD – CA.gov. Employee’s Withholding Allowance Certificate (DE 4)
Skip the state form and most states require your employer to default to the least favorable setting, typically single with zero allowances, which pulls the maximum amount from each check. That’s not ideal if you’re married or have dependents, because you’ll be lending the state an interest-free loan all year and waiting until you file to get the overpayment back.3EDD – CA.gov. Employee’s Withholding Allowance Certificate (DE 4)
Flat vs. Progressive Rates
How fast your withholding builds up depends on whether your state uses a flat or progressive tax rate. Flat-tax states charge the same percentage on every dollar of taxable income. Progressive-tax states apply higher rates as income rises through defined brackets. For 2026, state income tax rates range from 2.5 percent at the low end to 13.3 percent at the top, with the highest rate applying only to income above the top bracket threshold.
Penalties for Claiming False Allowances
Claiming allowances you’re not entitled to in order to shrink withholding can carry serious consequences. Under federal law, willfully providing false information on a withholding certificate is a criminal offense punishable by up to $1,000 in fines and up to one year in jail.4Office of the Law Revision Counsel. 26 USC 7205 – Fraudulent Withholding Exemption Certificate or Failure to Supply Information A separate $500 civil penalty applies to statements made without reasonable basis that reduce withholding below what you actually owe. Even without any fraud, underwithholding often triggers interest and late-payment charges on your state return, so getting allowances right up front saves trouble later.
States With No Personal Income Tax
Eight states impose no personal income tax on wages: Alaska, Florida, Nevada, South Dakota, Tennessee, Texas, Washington, and Wyoming. If you live and work exclusively in one of them, Boxes 15 through 17 will be blank and you won’t file a state income tax return.
Working in a no-income-tax state doesn’t automatically mean you owe nothing. If you live in a state that does tax income, your home state generally taxes all of your earnings regardless of where you performed the work.
Working in More Than One State
If you live in one state and work in another, your W-2 may carry entries for both states in Boxes 15 through 20. In the plain version of this situation, your work state withholds as a nonresident and your home state expects a return too. Without special rules, that would often mean double taxation. Two mechanisms usually prevent it.
Reciprocity Agreements
About 16 states and the District of Columbia keep reciprocity agreements with one or more neighboring states. Under these agreements, you pay income tax only to your home state, and your employer withholds accordingly. Live in Pennsylvania and commute to New Jersey, for example, and a reciprocity agreement between the two states means New Jersey won’t tax your wages. Your employer withholds for Pennsylvania only, and only one state appears on your W-2.
Reciprocity usually requires you to file an exemption form with your employer. Without that form, the work state may withhold anyway, and you’ll need a nonresident return to claim the money back.
Credits for Taxes Paid to Another State
Where no reciprocity agreement exists, most states offer a credit on your resident return for income taxes paid to another state. The credit stops you from paying full tax to both states on the same income. You’ll typically file a nonresident return in the work state first, then claim the credit when you file at home. The credit is limited to the lesser of the tax you paid the other state or the tax your home state would charge on that same income, so you always pay at least the higher of the two rates.
The Convenience of the Employer Rule
Remote workers face an extra wrinkle in a handful of states. Under the “convenience of the employer” rule, a state taxes your wages based on where the employer is located, not where you sit. If your employer’s office is in New York but you work remotely from Connecticut, New York may still claim the right to tax your wages unless you can show you’re working remotely out of business necessity rather than personal convenience.
Roughly eight states enforce some version of this rule, with New York being the most aggressive. Employers in these states are required to withhold as if the remote worker were physically present at the office unless the employee documents business necessity. Multi-state situations like this get genuinely complicated, and many people in this position benefit from professional tax help.
What to Do About Errors on Your W-2
Mistakes in the state boxes happen more often than you’d expect, especially for employees who changed addresses, worked in multiple states, or had mid-year adjustments. If the state abbreviation is wrong, the wages are off, or the withholding amount doesn’t match your pay stubs, contact your employer’s payroll department first. They’ll issue a corrected form called a W-2c, which reports the originally filed numbers alongside the corrected ones.5Internal Revenue Service. About Form W-2 C, Corrected Wage and Tax Statements
Don’t file your state return with numbers you know are wrong just because the deadline is close. If a corrected W-2 hasn’t arrived, filing a state extension buys time without triggering failure-to-file penalties in most states. An extension gives you extra time to file, not extra time to pay, so estimate what you owe and send a payment with the extension request to hold down interest.
Key Deadlines
Your employer must deliver your W-2 by January 31 following the tax year. For 2025 income, the deadline is January 31, 2026.6Social Security Administration. Deadline Dates to File W-2s If the 31st falls on a weekend or holiday, the deadline shifts to the next business day. If your W-2 hasn’t arrived by mid-February, contact your employer, and if that goes nowhere, the IRS can intervene on your behalf.
Most state income tax returns are due April 15, matching the federal deadline. A few states set different dates, so check with your state’s tax agency if you’re unsure. Filing late triggers penalties that vary by state but commonly run between 2 and 10 percent of the unpaid balance, plus interest that accrues from the original due date. Filing on time with a partial payment is almost always cheaper than not filing at all.