The fastest way to spot a paycheck error is to compare your pay stub against three things: your own record of hours, your pay rate and benefit elections, and last period's stub. Most mistakes show up as a difference in hours, rate, withholding or a deduction, and most are fixed on the next paycheck once you report them.
Below are the errors that come up most often, a worked example of a withholding mistake that can cost you at tax time, and the steps to take if payroll doesn't fix it.
The Most Common Paycheck Errors
| Error | Where to look on the stub | What it does |
|---|---|---|
| Missing hours or overtime | Earnings section: hours and rate | Lower gross and net pay |
| Wrong pay rate | Earnings section: rate column | Raise not applied, or wrong shift differential |
| Wrong W-4 information | Federal income tax line; filing status if shown | Too little or too much federal withholding |
| Wrong state or local tax | State and local tax lines | Tax withheld for the wrong place |
| Benefit deduction errors | Pre-tax and after-tax deductions | Missed, duplicated or wrong-amount premiums or 401(k) |
| Missing reimbursements | Non-taxable earnings or reimbursements | Out-of-pocket costs not repaid |
Hours and overtime
For non-exempt employees, federal law requires at least 1.5 times the regular rate for hours over 40 in a workweek. Overtime is figured by workweek, not by pay period, so a biweekly check with 50 hours one week and 30 the next still owes 10 overtime hours. Missing clock-ins, unapproved overtime that wasn't entered, and holiday weeks are common sources of mistakes.
Deductions that start, stop or double
Benefit changes at open enrollment, a new hire's first paychecks, and the first paycheck of the year are high-risk moments. A 401(k) percentage entered wrong, a health premium for coverage you dropped, or the same deduction listed twice can all slip through.
Work location
If you moved, changed offices or now work remotely, check that state and local taxes match where you live and work. Rules for working in one state and living in another vary, so compare against your state's calculator in our state directory.
Worked Example: A Filing Status Mistake
Some paycheck errors feel like good news at first. Say a single filer in New York earning $72,000 a year, paid biweekly, is set up in payroll as married filing jointly by mistake. Here's the estimated difference using our paycheck calculator:
| Per paycheck | Correct (single) | Error (married filing jointly) |
|---|---|---|
| Gross pay | $2,769.23 | $2,769.23 |
| Federal income tax | $269.62 | $164.62 |
| Social Security | $171.69 | $171.69 |
| Medicare | $40.15 | $40.15 |
| New York income tax | $126.58 | $103.42 |
| New York SDI | $1.20 | $1.20 |
| Net pay | $2,159.99 | $2,288.15 |
The paycheck is $128.16 larger, but federal withholding is $105 too low every time. Over 26 paychecks, that's about $2,730 less federal tax withheld than this worker's estimated withholding as a single filer, plus a shortfall in New York tax. That gap would show up as a balance due when they file. The New York paycheck calculator shows the full estimate.
The fix is to submit a corrected W-4 (and the state form, if your state uses its own) and ask payroll to confirm the change. Catching it early spreads the difference over fewer paychecks. Our guide on how to fill out a W-4 walks through each step.
How to Check Your Pay Stub Each Payday
- Check hours and rate. Multiply hours by rate for each earnings line and add overtime at 1.5× where it applies.
- Compare gross to last period. If it changed, there should be a reason: hours, a raise, a bonus or a holiday.
- Scan each deduction. Pre-tax and after-tax deductions should match your elections.
- Look at the YTD column. A year-to-date total that doesn't add up can reveal a missed or duplicated item. See what YTD means on a pay stub.
- Run an estimate. Enter your salary or hours, filing status, state and deductions in the calculator. A big gap from your actual net pay is worth a closer look.
Not every change is an error. Social Security stops once your wages for the year reach $184,500, benefit premiums change at open enrollment, and a bonus check is often withheld at a flat 22% federal rate. Our article on why your paycheck is smaller covers normal changes that can look like mistakes.
How to Fix a Paycheck Error
Report it to payroll in writing
Email payroll or HR with the pay date, what you expected, what you received, and how you calculated it. Attach your timesheet or a screenshot of your benefit elections. Written reports create a record and usually get faster answers than a hallway conversation.
Ask how and when it will be corrected
Underpayments are often corrected on the next regular paycheck, and some employers issue an off-cycle check for larger amounts. Ask which it will be, and check that the correction appears on your stub.
If you were overpaid
Report overpayments too. Employers generally can recover overpaid wages, but how they can do it, and whether they need your written agreement, depends on state law. If the overpayment and repayment happen in different tax years, ask payroll how it will affect your W-2.
If payroll doesn't fix it
For unpaid wages or overtime, you can contact your state labor department or the U.S. Department of Labor's Wage and Hour Division, which enforces federal minimum wage and overtime rules. Wage claims have time limits, so don't wait months. For withholding problems, the IRS Tax Withholding Estimator can help you decide what to put on a corrected W-4.
Records Worth Keeping
Keep every pay stub until you've checked it against your W-2 at the end of the year, and keep your own log of hours if you're paid hourly. Save copies of your W-4, benefit elections and any offer letter that shows your pay rate. These make any paycheck error much easier to prove.
Frequently Asked Questions
How long does an employer have to fix a paycheck error?
It depends on state law and the type of error. Many employers correct underpayments on the next payday; if yours won't, contact your state labor department.
Can I be fired for reporting a paycheck error?
Federal law protects employees from retaliation for complaining about unpaid minimum wage or overtime, and many states have similar protections. If you think you've faced retaliation, contact the Department of Labor or your state agency.
What if too little tax was withheld all year?
You'll generally owe the difference when you file. Updating your W-4 now reduces the gap for the rest of the year.
Is a smaller paycheck in January a paycheck error?
Not always. New benefit premiums, a reset Social Security deduction for high earners and new contribution elections often change January pay; compare line by line with December.
Sources
- U.S. Department of Labor: Fair Labor Standards Act
- U.S. Department of Labor: Overtime Pay
- IRS: About Form W-4
- IRS Tax Withholding Estimator
Run the numbers for your state
Written and checked against IRS, Social Security Administration and state tax agency publications for the 2026 tax year. General information, not tax, legal or financial advice. Read our editorial policy, calculation methodology and sources.