Why Payroll Deductions May Be Incorrect

A wrong payroll deduction is one of the most common payroll errors a small employer faces, and it is also one of the easiest to miss. The gross pay looks right, the hours look right, and the net pay still comes out wrong because one deduction line is off. The good news is that the fix follows the same path whether the cause is a stale withholding form, a missed election update, or a garnishment entered at the wrong amount.

This guide walks through why payroll deductions may be incorrect, from spotting a bad deduction line early to correcting it cleanly and keeping your records straight. If you are newer to payroll altogether, it helps to start with our guide on payroll processing basics before you dig into the deduction errors. For a closer look at how the deduction lines themselves work, see our guide on how payroll deductions work.

What Makes a Payroll Deduction Incorrect

A payroll deduction is incorrect when the amount withheld from an employee's gross pay does not match what should be withheld. The error can run in either direction. A deduction can be too high, which leaves the employee with less net pay than they earned, or too low, which leaves the employee with more net pay than they should receive and the employer short on what has to be sent to the agency or the benefit provider.

Every deduction line has a source. A statutory withholding comes from the employee's withholding form and their pay details. A voluntary deduction comes from the election the employee signed. A garnishment comes from the order that directed it. When the source and the run stop matching, the deduction comes out wrong. The correction is always the same, which is confirming the right amount, fixing the source, and updating the records so the change is easy to trace.

Common Causes of Incorrect Deductions

Most incorrect deductions come from a small set of causes. Knowing them helps you find the error fast and fix the right thing instead of the symptom.

• Stale withholding details. An employee updates a withholding form and the change never reaches the run, so the statutory withholding is calculated off the old filing status or the old allowances.
• Missed voluntary election updates. An employee starts, changes, or stops a retirement contribution or a health premium and the election is not entered before the next run, so the voluntary deduction runs at the old amount or keeps running after it should have stopped.
• Garnishments entered at the wrong amount. A garnishment order is entered with the wrong amount, the wrong priority, or the wrong end date, so the deduction does not match what the order directed.
• Percentage deductions off the wrong base. A deduction that is a percentage of pay is calculated off an old pay rate or an old hours total, so the amount is wrong even when the percentage is right.
• Deductions that never stopped. A voluntary deduction that should have ended keeps running because no one marked the end date, so the employee keeps paying into a benefit they left.

Each of these causes shares one root, which is a gap between the source document and the run. For a fuller look at the errors that show up alongside incorrect deductions, see our guide on common payroll mistakes.

Spot the Error Before Payday

The best correction is the one you never have to make, which is why catching a wrong deduction early matters. Run the prepay checks before pay goes out, and review the payroll register for the whole run on one page. Confirm the pay dates, the gross pay for each employee, the deduction lines, and the net pay, then confirm the total net pay matches the amount scheduled to leave the bank account.

Watch the deduction lines specifically. A deduction that jumps without a reason, a voluntary deduction that keeps running after an employee left a benefit, or a garnishment that does not match the order are all signs the source and the run have drifted apart. An incorrect deduction caught before payday is fixed by correcting the run, which avoids a correction on the next run and keeps the records clean from the start.

Steps to Correct an Incorrect Deduction

When you find an incorrect deduction, work through the steps in order so the correction stays clean and the records stay easy to trace.

1. Confirm the right amount. Identify the correct deduction amount and which employee the run affected before you change anything.
2. Find the source. Pull the withholding form, the voluntary election, or the garnishment order that should drive the deduction.
3. Fix the source. Update the withholding detail, the election, or the garnishment entry so the source and the run match again.
4. Stop the run if you can. If pay has not gone out yet, pause the run so you can correct it before the deposit leaves the bank account.
5. Tell the employee. If pay already went out, tell the employee about the incorrect deduction and confirm the correction before you apply it.
6. Correct the next run. If the deduction was too high, refund the extra on the next run or with a separate payment. If it was too low, withhold the missing amount on the next run.
7. Rerun the totals. Recalculate the gross pay, the deductions, and the net pay for the affected employee, and rerun the totals for the whole run.
8. Update the records. Keep the original run, the correction, the updated source document, and a short note about what caused the incorrect deduction so the fix is easy to trace.

Example: A Cafe Fixes a Stale Withholding Form

Consider a small cafe with hourly employees paid biweekly. After a run goes out, an employee points out their net pay dropped with no change in hours. The owner checks the run and finds the employee had updated a withholding form a month earlier, but the new filing status was never entered, so the statutory withholding kept running off the old single status.

The owner pulls the updated withholding form, enters the new filing status, and reruns the deduction for the affected pay periods. Because the withholding was too high, the owner refunds the extra amount on the next run as a separate line. The owner tells the employee about the correction, reruns the totals, and keeps the updated form, the correction, and a short note about the stale detail with the payroll records. The example shows how a stale withholding form turns into a clean correction when you fix the source first.

Example: A Shop Corrects a Missed Election Update

Take a small retail shop with a mix of hourly and salaried staff paid semimonthly. After a run goes out, the owner notices one employee's net pay is higher than usual. The owner checks the run and finds the employee had dropped a health plan at the start of the month, but the election was never updated, so the premium kept running and the employee kept paying into a benefit they left.

The owner updates the election to stop the premium, tells the employee about the incorrect deduction, and refunds the extra premium amounts on the next run as a separate line. The owner reruns the totals and saves the election change and a short note about the missed update with the payroll records. For more on what to keep on file, see our guide on payroll records employers should keep. The example shows how a missed election update is corrected on the next run with a clean record.

How to Prevent the Next Incorrect Deduction

A correction is cleaner when the next run does not repeat the same incorrect deduction. The habits below keep the source and the run from drifting apart.

• Keep each employee's withholding details and voluntary elections current, and enter changes from signed documents before the next run.
• Confirm garnishment orders against the order before each pay run, including the amount, the priority, and the end date.
• Run the prepay checks every run, including the pay dates, the gross pay, the deduction lines, and the net pay.
• Review the payroll register for the whole run before pay goes out, and watch the deduction lines for jumps without a reason.
• Reconcile the total net pay to the bank account every run, and reconcile the month against the bank statement.

Incorrect Payroll Deduction Correction Checklist

Use this checklist when you find an incorrect payroll deduction. Work through it in order so the correction is clean, the right amount is withheld or refunded, and the records stay easy to trace.

Getting Started

An incorrect payroll deduction is fixable, and the fix is cleaner when you confirm the right amount, fix the source, correct the next run, and update the records. Work through the steps above, and your next run starts from the right numbers instead of the last wrong deduction.