What Is Fed W/H on My Paycheck and How It Works

The “Fed W/H” line on your paycheck is federal income tax withholding: the money your employer takes out of each check and sends to the IRS as a prepayment against the income tax you’ll owe for the year. The amount isn’t random and it isn’t a flat percentage. It comes from the Form W-4 you filled out when you started the job, run through IRS-approved payroll math for your filing status, pay frequency, and gross wages that period.¹

When you file your return next spring, every dollar withheld under Fed W/H counts as tax you’ve already paid. If it covered your bill, you’re done. If it overshot, you get a refund. If it fell short, you owe the difference.

What Determines the Amount

Your employer’s payroll system looks at two things: what you put on your W-4, and how much you earned this pay period. Since 2020, the W-4 no longer uses “allowances.” It uses dollar amounts and checkboxes that plug straight into the calculation.¹

Step 1 sets your filing status (single, married filing jointly, or head of household), which picks the tax brackets and standard deduction the payroll system uses.
Step 2 handles multiple jobs or a working spouse. Skip it when it applies and you will almost certainly under-withhold.
Step 3 is where you enter dependent credits: $2,200 per qualifying child under 17 for 2026, and $500 for each other dependent. These reduce the tax withheld from every check.²
Step 4(a) lets you add outside income (interest, dividends, retirement distributions) so more tax comes out of your paycheck to cover it.
Step 4(b) lets you account for itemized deductions above the standard deduction ($16,100 single, $32,200 married filing jointly for 2026), which reduces withholding.³
Step 4(c) is a flat extra dollar amount per check on top of the normal math. People use it as a safety margin when their situation is messy.

Behind the scenes, payroll runs those inputs through one of two IRS methods in Publication 15-T: the wage bracket tables for a straightforward lookup, or the percentage method formula that most software uses. Both are designed to produce the same result. Either way the withholding should track the 2026 federal brackets, which run from 10% on the first $12,400 of taxable income for a single filer up to 37% on income above $640,600.³

If You Never Turned In a W-4

Your employer doesn’t guess. They’re required to withhold as if you were single with no dependents and no other adjustments, which is the setting that takes out the most tax.¹ Your paychecks shrink, and you probably get a big refund at filing time.

Claiming Exempt

If you had zero federal income tax liability last year and expect the same this year, you can write “Exempt” on your W-4 and stop federal income tax withholding entirely. Both conditions have to be true.² An exempt W-4 expires each year; you need to file a fresh one by February 15 to keep it in place. Miss that date and your employer reverts to the single, no-adjustments default.⁴

Why Your Fed W/H Might Look Wrong

A few situations regularly throw off the number on the line.

Bonuses and commissions. Supplemental wages are usually withheld at a flat 22% on the first $1 million, then 37% on anything above. That’s why a bonus check often looks over-taxed. If your real bracket is 12% or 24%, the extra withholding comes back as a refund when you file.⁴

A second job or a working spouse. Each employer withholds as if their job is your only income, which means each one applies the lower brackets. Combined, they take out too little. Step 2 of the W-4 gives you three ways to fix this: the online Tax Withholding Estimator (Step 2a) is the most accurate; the Multiple Jobs Worksheet (Step 2b) is best for three or more jobs or very uneven pay; the checkbox (Step 2c) is the simplest but only works when there are exactly two jobs and the lower-paying one earns more than half what the higher one does, with the box checked on both W-4s.²

Tips or overtime. Starting with 2025 income, workers in tipped occupations can deduct up to $25,000 in qualified tips, and workers paid overtime can deduct the premium portion (generally the “half” in time-and-a-half) up to $12,500, or $25,000 filing jointly. Both deductions phase out above $150,000 in modified adjusted gross income ($300,000 joint).⁵ Payroll systems aren’t automatically pulling less from each check to reflect these, so if you earn either kind of pay, your Fed W/H is probably running high. You can use Step 4(b) or the IRS estimator to bring it back in line.

How to Change Your Fed W/H

To move the number up or down, submit a new W-4 through your employer’s HR or payroll portal. The old one stays in effect until you replace it. Any real life change, such as marriage, divorce, a new baby, or picking up or dropping a second job, is a reason to update.

Before you fill out the new form, run the IRS Tax Withholding Estimator. It’s free, and it’s more accurate than doing the W-4 worksheets by hand. You feed in your income, deductions, credits, and current withholding, and it tells you exactly what to write on the new W-4 to hit whatever target you want, whether that’s breaking even, a small refund, or nothing owed.⁶ Have your recent pay stubs ready, plus your spouse’s if you file jointly, and your last tax return if you have investment income, self-employment earnings, or plan to itemize. Budget about 25 minutes. The 2026 version accounts for the tips and overtime deductions and the increased Child Tax Credit.⁷

What Fed W/H Is Not

Fed W/H is federal income tax only. The other tax lines on your stub are separate and your W-4 doesn’t control them.

Social Security (OASDI) is 6.2% of gross wages up to $184,500 for 2026. Once you hit that cap, the withholding stops for the rest of the year. Maximum you can pay: $11,439.⁸
Medicare is 1.45% of all gross wages with no cap.⁹
Additional Medicare Tax adds another 0.9% on wages above $200,000. Your employer starts withholding it once your wages pass $200,000 regardless of filing status; if you file jointly and your combined income stays under $250,000, you claim the excess back on your return.⁹

State and local income taxes, if your state or city has them, use their own forms and their own rules.

One other thing that isn’t Fed W/H: backup withholding. That’s a 24% withholding the IRS orders on non-wage income like interest, dividends, or freelance payments, usually because a taxpayer ID is missing or wrong or because past interest and dividend income was underreported. You’d see it on a 1099, not on your W-2 paycheck. Fixing the underlying issue (correct TIN, resolved underreporting, missing returns filed) stops it.¹⁰

How Fed W/H Settles Up at Tax Time

By January 31, your employer sends you a W-2. Box 2 shows the total Fed W/H remitted to the IRS on your behalf for the year.¹¹ You put that figure on Line 25a of Form 1040, where it’s compared against your actual tax liability.¹² Withheld more than you owe: refund. Withheld less: you write a check.

Owing a little is normal. Owing a lot can trigger the Estimated Tax Penalty, which the IRS generally applies when your balance due exceeds $1,000 after subtracting withholding and refundable credits.¹³ You avoid it by meeting one of two safe harbors: withholding and estimated payments covered at least 90% of this year’s tax, or at least 100% of last year’s (110% if your prior-year AGI was over $150,000). Interest on any underpayment adjusts quarterly; it’s 7% for the first quarter of 2026 and 6% for the second.¹⁴

Checking the estimator once a year, and again after any big life change, is the most reliable way to keep the Fed W/H number where you want it.

1
Internal Revenue Service. Topic No. 753, Form W-4, Employees Withholding Certificate
2
Internal Revenue Service. Form W-4, 2026 Employees Withholding Certificate
3
Internal Revenue Service. IRS Releases Tax Inflation Adjustments for Tax Year 2026
4
Internal Revenue Service. Publication 15 (2026), (Circular E), Employers Tax Guide
5
Internal Revenue Service. How to Take Advantage of No Tax on Tips and Overtime
6
Internal Revenue Service. Tax Withholding Estimator
7
Internal Revenue Service. Updated Tax Withholding Estimator Lets Millions of Taxpayers Take One, Big, Beautiful Bill Changes Into Account When Calculating Their Withholding
8
Social Security Administration. Contribution and Benefit Base
9
Office of the Law Revision Counsel. 26 U.S. Code 3101 – Rate of Tax
10
Internal Revenue Service. Backup Withholding
11
Social Security Administration. Deadline Dates to File W-2s
12
Internal Revenue Service. Instructions 1040 (2025) – Section: Line 25 Federal Income Tax Withheld
13
Internal Revenue Service. Underpayment of Estimated Tax by Individuals Penalty
14
Internal Revenue Service. Quarterly Interest Rates