Your W-4 tells your employer how much federal income tax to hold back from each paycheck. Fill it out wrong and you either get a fat refund in April (money you loaned the government for free all year) or a surprise tax bill. Fill it out right and the amount taken out lands close to what you actually owe.
If someone told you to "claim 0 or 1 allowances," ignore them. That advice is from the old W-4. The IRS redesigned the form in 2020 and allowances no longer exist. There is no line to claim them on. The new form asks about your filing status, your other jobs, your dependents in dollars, and any extra you want held out. That's it.
Why allowances are gone
The old W-4 used "allowances" — a fuzzy number that stood in for your deductions. More allowances meant less tax withheld. Nobody could explain how one allowance mapped to real dollars, so people guessed, and the guesses were often wrong.
The 2020 redesign threw the concept out. Instead of a made-up number, the form now asks for actual dollar figures: how much your dependents are worth in tax credits, how much other income you have, how much extra you want withheld. Everything is concrete. If you're looking at a W-4 with a box for "total number of allowances," it's an outdated form — don't use it.
Step 1: Filing status
This is the only required part. Pick one:
- Single or Married filing separately
- Married filing jointly (or qualifying surviving spouse)
- Head of household — you're unmarried and pay more than half the cost of keeping up a home for a qualifying person
Your status sets which standard deduction and tax brackets get baked into your withholding. In 2026 the standard deduction is $16,100 for single filers and $32,200 for married filing jointly. If you only fill out Step 1 and sign, your withholding is calculated as if you have no other jobs, no dependents, and no adjustments — which is fine for a lot of single-job households.
Step 2: Multiple jobs or a working spouse
Check this box if you have more than one job, or if you're married filing jointly and your spouse also works.
Here's why it matters. Each job withholds as if it's your only income, using the full standard deduction. When you have two paychecks, that deduction gets applied twice, so not enough tax comes out overall — and you owe at year-end. Checking the box tells the calculation to withhold at the higher rate that two incomes actually land in.
Check it on the W-4 for the highest-paying job only. If you check it on both, too much comes out.
Step 3: Claim dependents
If your total income is under $200,000 ($400,000 married filing jointly), enter your dependent credits here as a dollar amount:
- Qualifying children under 17 × $2,000
- Other dependents × $500
So two young kids is $4,000. Enter the total. This directly lowers the tax withheld from each check, spreading the credit across the year instead of you waiting to claim it all at tax time.
Step 4: Other adjustments (optional)
Three optional fields for fine-tuning:
- (a) Other income — interest, dividends, retirement income not from a job. Adding it here holds out extra so you don't owe on that income later.
- (b) Deductions — only if you itemize and your itemized deductions beat the standard deduction. This reduces withholding.
- (c) Extra withholding — a flat dollar amount to take out of every paycheck on top of everything else. The simplest lever if you just want more held back.
Doing it in Payrollix
You don't fill out a paper form. All of these fields live in the W-4 editor in your Employee Portal, laid out step by step. For the exact click-path — where the button is, what each field is labeled, when changes take effect — see Profile & W-4. Changes apply to your next paycheck, not retroactively, so update it before the pay period you want it to hit.
If your numbers are complicated (two high incomes, side income, itemizing), the IRS Tax Withholding Estimator does the math and hands you exact figures to type in. There's a link to it right on the W-4 page.
Related: Profile & W-4 · Adjust your tax withholding · Update your W-4 after marriage or a new child.