Common payroll mistakes and how to fix them

The 12 most common payroll mistakes

Several of these come from one root cause: a classification set once and never reviewed. Our guides to W2 vs 1099 workers and exempt vs non-exempt employees cover the tests.

How to fix a payroll mistake, step by step

1. Stop the next payroll from repeating it. Fix the rate, deduction or setting first, then correct the past.
2. Find every affected pay period. Pull the payroll register for the employee, or for everyone if the error was a company-wide setting such as a tax rate.
3. If you underpaid, pay the difference now. Run an off-cycle payroll rather than waiting for the next payday. Under the FLSA, wages are due on the regular payday for the period worked.
4. If you overpaid, check your state's rules before you deduct. States set different limits on taking money back from later paychecks, so get the employee's written agreement and check the state labor department's rules first.
5. Correct withholding in the same year when you can. An error caught before year-end can usually be fixed on later paychecks so the W-2 comes out right.
6. Amend what you already filed. A Form 941 for a closed quarter is corrected on Form 941-X; a W-2 already sent is corrected on Form W-2c. Fix the matching state wage report too.
7. Tell the employee in writing. Say what was wrong, what you paid or will recover, and when.
8. Keep the paper trail. Corrected registers, the notice to the employee and copies of amended returns.

Payroll mistakes and the law: what you owe when pay comes out wrong

Federal law sets a simple rule and leaves most of the detail to states. Under the FLSA, wages are due on the regular payday for the period worked. The Department of Labor says federal law does not require employers to hand a departing employee the final paycheck immediately, and it tells workers who have not been paid by the regular payday to contact its Wage and Hour Division or the state labor department.

State final pay deadlines are where an honest mistake turns into a claim. Examples from our state research:

Every state's rule is on its page in the payroll tax hub, and the full set of federal and state duties is in our payroll compliance checklist.

Tax deposit and filing mistakes

Deposit dates follow your deposit schedule, not your return due date, and that is where new employers slip. The IRS rules from Topic 757:

• Your schedule comes from the lookback period. For 2026 it is July 1, 2024 to June 30, 2025. For 2027 it is July 1, 2025 to June 30, 2026, so check it before your first 2027 payroll.
• Monthly depositors ($50,000 or less in the lookback period) deposit by the 15th of the next month.
• Semiweekly depositors deposit Wednesday, Thursday and Friday paydays by the next Wednesday, and Saturday through Tuesday paydays by the next Friday.
• Small quarters: under $2,500 of tax for the quarter can be paid with a timely Form 941 instead.
• FUTA: deposit once the quarterly amount passes $500, by the last day of the month after the quarter ends.

Dates that land on a weekend or holiday move to the next business day. That is why Q3 2026 Form 941 is due November 2, 2026 (October 31 is a Saturday) and the 2026 W-2s, Form 940 and Q4 941 are due February 1, 2027. The full year-end list is in the payroll year-end checklist.

When the payroll company makes the mistake

The most common complaint we found about payroll providers is a tax filing error with the penalty left on the customer. Reviewers describe "thousands of dollars in penalties, interest, and fees" (Gusto, Trustpilot, October 2, 2026), a misfiled 941 after which "the IRS took over $31000.00" from an ERC refund (ADP, Trustpilot, October 5, 2026), and unfiled quarterly reports followed by a state lien notice (Paychex, ConsumerAffairs, October 31, 2025).

Whether you get reimbursed usually turns on a deadline in the provider's terms, not on who was at fault:

• Gusto reimburses penalties from its failure to remit on time if you send it the agency notice at least 30 days before the response date.
• QuickBooks Workforce Elite pays penalties and interest up to $25,000 a year if you email the full notice within 15 days of its date. Other QuickBooks plans have no guarantee we could find.
• Wave pays if it is at fault, after you pay the penalty and send proof.
• ADP RUN covers penalties from its errors, and interest only when it held your tax money past the due date.
• OnPay covers penalties from its negligent errors; interest from its own errors is not addressed.

None of these promises cover the tax itself, or errors that start with data you entered. See how providers compare on this in our payroll software rankings.

Mistakes when you switch payroll providers mid-year

A switch is the riskiest week in a payroll year. One employer on Hacker News said a botched switch sent their unemployment insurance rate from 0.8% to 12.75% (August 17, 2026). A seasonal business owner said the new provider "does not file wage reports" in the quarter they had no payroll (August 27, 2026).

• File zero-wage quarterly reports in quarters with no payroll, if your state requires them.
• Load year-to-date wages into the new system so Social Security, FUTA and SUTA wage bases do not restart.
• Hand over the state accounts: give the new provider your SUTA and withholding account numbers and any power of attorney it needs, and confirm the old one stops filing.
• Download everything first. Wave says you lose access to payroll data at the end of the month you cancel. Gusto keeps read-only access but charges $100 federal, $100 per state and $5 per W-2 or 1099 if it files your final returns.

The cleanest switch date is January 1. The costs of each provider are in what payroll services cost.

How to prevent payroll mistakes

1. Review each payroll before you approve it. Compare gross pay and hours to the last run and question any change over a few percent.
2. Have a second person approve new hires, pay rate changes and off-cycle runs.
3. Check federal deposits yourself. Enroll your EIN in EFTPS, the Treasury's payment system, and match deposits to your payroll registers each month.
4. Log in to your state accounts each quarter and confirm the wage report and payment posted.
5. Review classifications once a year: contractors against the IRS and state tests, salaried staff against the $684 floor and duties tests.
6. Keep a calendar of deposit, 941, W-2 and new hire deadlines, with the weekend and holiday shifts already applied.

If you are still choosing how to run payroll, how to set up payroll walks through the setup that avoids most of the errors above, and in-house vs outsourced payroll compares who does the work.