How to Fill Out Form W-4 (2026)
Your W-4 is the form that tells your employer how much federal income tax to withhold from each paycheck. Get it right and your withholding roughly matches your actual tax bill — no big refund, no nasty surprise in April. Get it wrong and you either loan the government money all year or owe a lump sum at filing.
The current W-4 (redesigned in 2020, same structure for 2026) has five steps. Most people only need Steps 1 and 5. Here's what each step actually asks for.
The five steps, in plain English
Step 1 — Personal information. Your name, address, Social Security number, and filing status (single, married filing jointly, or head of household). This is also where you pick the filing status your withholding is calculated under — it doesn't have to match what you'll actually file, but it should, or your withholding will be off.
Step 2 — Multiple jobs or spouse works. Only complete this if you hold more than one job at a time, or you're married filing jointly and your spouse works. Three options, pick one: - (a) Use the IRS Tax Withholding Estimator online for the most accurate result. - (b) Fill out the Multiple Jobs Worksheet on page 3 of the W-4 — it computes an extra withholding dollar amount. - (c) Check the box — but only if there are exactly two jobs in the household and they pay roughly similar amounts. This is the simplest option and the right one for most two-earner couples.
Step 3 — Claim dependents. If your total income is $200,000 or less ($400,000 or less if married filing jointly), multiply: $2,200 for each qualifying child under 17 and $500 for each other dependent (2026 figure per IRS; OBBBA raised it from $2,000 starting tax year 2025). Enter the total dollar amount. This directly reduces withholding.
Step 4 — Other adjustments (optional). Three lines: (a) other income not from jobs (interest, dividends, side-gig income) — entering it here withholds extra to cover it; (b) deductions beyond the standard deduction, using the Deductions Worksheet; (c) any extra tax you want withheld per pay period, as a flat dollar amount. Step 4(c) is the manual override — useful if bonuses or a side job consistently leave you short.
Step 5 — Sign and date. An unsigned W-4 isn't valid. Give it to your employer; you don't send it to the IRS.
The three mistakes that cost people money
1. Ignoring Step 2 with two incomes. This is the big one. Withholding tables assume your job is your only income. Two $60,000 jobs look like one $60,000 job to each employer's payroll system — but your real tax is computed on $120,000. The gap lands on you in April.
2. Never updating it. Marriage, divorce, a baby, a second job, a big raise — all change your tax picture. There's no rule against submitting a new W-4 mid-year; most payroll departments process one within a pay cycle or two.
3. Checking "exempt" when you don't qualify. You can only claim exempt if you owed zero federal tax last year and expect to owe zero this year. Getting this wrong means zero withholding and a full bill in April, possibly plus an underpayment penalty.
Worked example: why the second job creates a shortfall
Single filer, 2026. Main job pays $65,000; second job pays $20,000. You fill out the W-4 for the main job only and skip Step 2. Your second employer withholds a little, but let's see the shape of the problem (illustrative — federal income tax only, 2026 single standard deduction $16,100):
| Income considered | Federal tax | |
|---|---|---|
| Withholding base (main job only) | $65,000 → taxable $48,900 | 10% × $12,400 = $1,240; 12% × $36,500 = $4,380 → $5,620 |
| Actual liability (both jobs) | $85,000 → taxable $68,900 | $1,240 + 12% × $38,000 = $4,560; 22% × $18,500 = $4,070 → $9,870 |
| Shortfall | ≈ $4,250 |
That $4,250 doesn't vanish — it shows up on your return. Step 2 exists precisely to close this gap: the worksheet would have told you to add extra withholding per paycheck at the main job. (In reality your second employer withholds something too, which shrinks the gap — but the direction is always the same.)
What to do after you file it
Run your numbers through our US Take-Home Pay Calculator — enter your salary, filing status, and state, and compare the calculator's per-paycheck federal withholding against what's actually on your pay stub. If they don't roughly match, your W-4 needs another look.
FAQ
Do I need to fill out a new W-4 every year? No. Your W-4 stays in effect until you submit a new one. But review it after any major life or income change — that's when withholding drifts off target.
What's the difference between allowances and the current W-4? The old W-4 (pre-2020) used "allowances" — a confusing number you tweaked up or down. The current form replaced allowances with dollar amounts for dependents, other income, and deductions. If you haven't touched your W-4 since 2019, your old allowances were converted automatically, but it's worth redoing the form fresh.
My spouse and I both work. Should we both check the Step 2 box? No — only one of you should use a Step 2 method, or you'll double-count the adjustment. Pick one approach (the checkbox is simplest for two similar-paying jobs) and put it on one spouse's W-4.
Can I just have extra withheld to be safe? Yes — Step 4(c) lets you add any flat dollar amount per pay period. It's the simplest way to cover side income or kill an April surprise. Just don't overdo it: extra withholding is an interest-free loan to the Treasury.
Does the W-4 affect state withholding? The federal W-4 drives federal withholding only. Many states have their own withholding forms (California's DE 4, New York's IT-2104, and others). Ask your payroll department which state form you need.
Data sources
- IRS Form W-4 and instructions (2026 revision): five-step structure, Step 2 options, dependent amounts ($2,200 / $500), $200,000 / $400,000 income limits for Step 3. CTC $2,200 per IRS Child Tax Credit page (OBBBA, from tax year 2025).
- IRS Publication 15 (2026): withholding tables and methods employers use.
- Federal figures in the worked example: 2026 standard deduction $16,100 (single); brackets per IRS Rev. Proc. 2025-32 (IR-2025-103, Oct 9, 2025) (10% to $12,400; 12% to $50,400; 22% above).
Estimates only, not tax advice.