How to Fill Out Your W-4 When You Start a New Job

If you’re starting a new job, filling out a W-4 comes down to five numbered steps, but most people only need three of them: enter your name and filing status in Step 1, add up your dependent credits in Step 3 if you have any, and sign in Step 5. Steps 2 and 4 exist for specific situations — a second job, a working spouse, non-wage income, or itemized deductions — and you skip them otherwise. The form tells your employer how much federal income tax to pull from each paycheck, and the federal system runs pay-as-you-go, so what you put here shapes every check for the rest of the year.¹

What to Have in Front of You

Pull these together before you open the form. Your employer withholds based on what you report, so bad information rides along on every paycheck until you file a new W-4 to fix it.²

Your full legal name as it appears on your Social Security card, your Social Security Number, and your current address.
The filing status you plan to use: single, married filing jointly, married filing separately, or head of household.
The number and ages of any qualifying children under 17 and any other dependents you’ll claim.
Rough totals for interest, dividends, retirement distributions, or side-job income that no one is withholding on.
Estimates for itemized deductions (mortgage interest, state and local taxes, charitable contributions) if you plan to itemize.
A recent pay stub from any other job you hold, or your spouse’s job if you file jointly.

Step 1: Personal Information and Filing Status

Write your name, address, and Social Security Number, then check the box for your filing status. That checkbox sets the standard deduction your employer bakes into every paycheck. For 2026, the standard deduction is $16,100 for single filers and married filing separately, $32,200 for married filing jointly, and $24,150 for head of household.³ The wrong box here means the wrong deduction on every check.

Step 2: Only If You Have Another Job or a Working Spouse

Complete Step 2 only if you hold more than one job at the same time, or you file jointly and your spouse also works. When two incomes land in the same household, the combined total can push you into a bracket that neither job’s payroll system sees on its own. Skipping Step 2 in a two-income household is one of the most common reasons people owe money in April.

Pick one of the three options:⁴

Option (a) is the IRS Tax Withholding Estimator at irs.gov/W4App. It’s the most accurate route. Have your recent pay stubs, your last tax return, and estimates of any non-wage income ready, and the tool gives you the exact figures to write on the form.⁵
Option (b) is the Multiple Jobs Worksheet included with the W-4 instructions. It’s a paper calculation, a little less precise than the online tool, but it works without internet access.
Option (c) is the two-jobs checkbox. Available only when exactly two jobs are involved (yours alone, or yours and your spouse’s), it splits the standard deduction and brackets evenly between them. This is fine when the two jobs pay similar wages. If one pays much more than the other, it tends to over-withhold.

If you use option (a) or (b), fill out Steps 3 and 4 only on the W-4 for the higher-paying job. Leave those steps blank on the other W-4 so credits and deductions aren’t counted twice.

Step 3: Claiming Dependents

Step 3 lowers your withholding to reflect credits you’ll claim on your return. For 2026, multiply each qualifying child under 17 by $2,200 and put the total on line 3(a).⁴ Other dependents — children 17 or older, or qualifying relatives — go on line 3(b) at the applicable credit amount. Add the two lines and write the total on line 3.⁶

A child has to meet specific IRS tests: under 17 on December 31, lived with you more than half the year, didn’t provide more than half of their own support, and stands in a qualifying relationship to you (son, daughter, stepchild, eligible foster child, and certain others).⁷ If you file jointly and both spouses work, only one of you should claim dependents in Step 3, and typically it’s the higher earner.

Step 4: Optional Adjustments

Three optional lines let you fine-tune the withholding number.

Line 4(a) is for income you expect this year that won’t have tax withheld — interest, dividends, retirement distributions, freelance income. Adding it here raises your withholding to cover the tax on that money.
Line 4(b) is for itemizers. If your expected itemized deductions exceed your standard deduction, enter the difference so your employer withholds less. The Deductions Worksheet with the W-4 instructions walks you through the number.
Line 4(c) is a flat extra dollar amount to withhold from every paycheck. It’s useful when your tax picture is hard to estimate — self-employment income on the side, rental income, unpredictable investment gains.

Step 5: Sign and Date

The form isn’t valid until you sign it, and you sign under penalty of perjury.⁴ Handwritten or electronic signatures both work, depending on how your employer runs payroll.

Claiming Exempt From Withholding

You can claim complete exemption from federal income tax withholding only if two things are true: you had no federal income tax liability last year, and you expect none this year.⁴ To claim it, write “Exempt” in the designated space, fill in Steps 1(a), 1(b), and 5, and skip everything else. No federal income tax comes out of your checks.

Exempt status lasts one calendar year. To stay exempt, you file a fresh W-4 by February 15 of the following year. Miss that deadline and your employer has to start withholding as if you were single with no adjustments, which is close to the highest rate.⁸ Claiming exempt when you don’t qualify leads to a large bill plus penalties when you file.

When to Redo Your W-4 Later

The W-4 isn’t a one-time form. The IRS recommends checking it whenever your life or finances shift.⁹ Some events actually require a new W-4 within 10 days — specifically, changes that reduce the withholding allowances you’re entitled to claim.¹⁰ Common triggers:

Marriage or divorce, which changes your filing status, standard deduction, and brackets.
Gaining or losing a dependent: a new baby raises your credits; a child turning 17 or moving out lowers them.
Starting or ending a second job, or a spouse starting or ending one.
A big income change: a raise, significant investment gains, or new self-employment income.
Buying a home, if mortgage interest and property taxes now push you toward itemizing.

When the change means you should be withholding less (a new child, for example), updating is optional but usually in your favor, because otherwise you’re loaning the government money interest-free until you file. When the change means you should be withholding more (a divorce that shifts you from joint to single), the 10-day rule kicks in.

What Happens If You Get It Wrong

If too little is withheld across the year, you may owe an underpayment penalty. You generally avoid it if you owe less than $1,000 after withholdings and credits, or you paid at least 90 percent of the current year’s tax, or at least 100 percent of the prior year’s tax, whichever is less.¹¹ When the penalty applies, interest runs at the federal short-term rate plus three percentage points, compounded daily.¹²

Putting false information on a W-4 to cut your withholding carries a separate $500 civil penalty per false statement.¹³ In some cases the IRS also sends your employer a “lock-in letter” that overrides your W-4 and sets your withholding at a rate the IRS determines. Once a lock-in letter is in place, your employer can’t lower the withholding below that rate without IRS approval.

Once your first check hits, look at the pay stub. Confirm the filing status and withholding amount match what you put on the form, and submit a corrected W-4 right away if anything looks off.

1
Internal Revenue Service. Pay As You Go, So You Won’t Owe: A Guide to Withholding, Estimated Taxes and Ways to Avoid the Estimated Tax Penalty
2
Office of the Law Revision Counsel. 26 U.S. Code 3402 – Income Tax Collected at Source
3
Internal Revenue Service. IRS Releases Tax Inflation Adjustments for Tax Year 2026
4
Internal Revenue Service. Form W-4 (2026) Employee’s Withholding Certificate
5
Internal Revenue Service. IRS Tax Withholding Estimator Helps Taxpayers Get Their Federal Withholding Right
6
Internal Revenue Service. Child Tax Credit
7
Internal Revenue Service. Dependents
8
Internal Revenue Service. Topic No. 753, Form W-4 Employees Withholding Certificate
9
Internal Revenue Service. About Form W-4, Employee’s Withholding Certificate
10
Internal Revenue Service. Publication 505, Tax Withholding and Estimated Tax
11
Internal Revenue Service. Estimated Taxes
12
Internal Revenue Service. Quarterly Interest Rates
13
Office of the Law Revision Counsel. 26 U.S. Code 6682 – False Information With Respect to Withholding