A year-end withholding check can help you see whether the federal income tax coming out of your pay is on track. With only a few paychecks left, a small change in each one may not close a large gap. Start with current records, then decide what action fits your situation.
Know what withholding does
Federal income tax withholding is money your employer sends to the IRS from your pay during the year. Your final tax depends on your full-year income, deductions, credits, and other facts. Your tax return compares the tax due with payments and applicable credits.
A refund generally means your payments and refundable credits exceed your final tax. A balance due means they do not cover it. A refund is not a measure of your total tax, and a larger paycheck today can mean a smaller refund or a larger bill later. Read IRS Publication 505.
Gather the numbers before you start
Use current amounts rather than guessing from take-home pay. If you file jointly, include your spouse’s relevant income and withholding too. The estimator can account for income from more than one job and other sources.
Your latest statement shows both the amount for that pay period and the year-to-date total. If your recent pay was unusual, gather enough information to estimate your remaining income accurately.
The IRS lists pay statements and other income information among the records needed to use its tool. Check the estimator preparation guidance.
Account for changes during the year
A new job, a second job, a spouse starting or stopping work, marriage, divorce, or a change in dependents can affect the result. So can a raise, bonus, investment income, or a change in deductions or credits.
Enter your best estimate for the whole year, including what already happened and what you expect before December 31. Do not assume the amount withheld from one job covers every source of income. The IRS recommends checking after personal or financial changes. See Publication 505.
Run the IRS estimator
Open the official tool
Use the IRS Tax Withholding Estimator. It estimates federal income tax and compares it with expected payments.
Enter the year-to-date figures
Use wages and federal withholding from your records. Add expected income and payments for the rest of the year.
Review the estimate
Check the projected refund or amount due. Revisit any input that does not reflect your current situation.
Choose a next step
If a change makes sense, follow the tool’s instructions for a new Form W-4. Give the completed form to your employer.
The estimator is free. The IRS says it can help employees complete a new W-4 and retirees complete a W-4P when a change is needed. Open the IRS estimator. The result is an estimate, not a filed return or a guarantee of a refund.
If your situation is complex, such as substantial self-employment or investment income, use the additional IRS guidance or ask a qualified tax professional. Estimated tax payments may also be relevant when income is not sufficiently covered by withholding. Read the IRS guide to withholding and estimated tax.
Count the paychecks that can still change
Ask payroll when a new W-4 must arrive to affect the next check. Count only the checks that payroll confirms can reflect the change. A form submitted late in the year may affect fewer checks than you expect.
A shortfall in the estimate does not automatically equal the extra withholding you should enter on one paycheck. The tool uses your information to suggest an approach. Review your cash needs before you submit a change, and consider the IRS guidance on estimated payments if withholding alone is not enough. Underpayment penalties depend on the facts and timing of payments. See Publication 505.
Submit the form and check again
Form W-4 tells your employer how to calculate federal income tax withholding. It is given to the employer, not filed with your tax return. You can provide a new form when you want to change your withholding. See the IRS Form W-4 page.
Keep a copy and check the next pay statement after payroll processes it. Compare the federal income tax line with your expectations. If the change is missing or the timing is unclear, contact payroll.
A change made to catch up late in 2026 can continue into 2027. Review your withholding early in the new year, when a full year of pay may produce a different result. The IRS warns that a midyear change can cause too much or too little withholding when applied to the next full year. See the IRS employer tax guide.
Sources and update
Checked November 2, 2026. This article covers federal income tax withholding for a general U.S. audience. Estimates and examples do not determine an individual tax result.
Frequently asked questions
Does a refund mean I paid no income tax?
No. A refund generally means your payments and refundable credits exceed your final tax. Your return shows the calculation of your tax.
Do I send a new W-4 to the IRS?
No. Give the completed Form W-4 to your employer. Ask payroll when it will take effect.
Can I fix a large projected shortfall with the last paycheck?
Not necessarily. The amount that can be withheld depends on the pay remaining and payroll timing. Review the estimator and IRS guidance on estimated payments.
Should I check again in January?
Yes. A late-year adjustment can continue into the new year. Recheck using your new-year pay and expected circumstances.