How to Fill Out Form W-4 (2026)

The W-4 has five steps and only two of them are optional in practice. Most withholding problems come from Step 2, which people skip because it looks like it does not apply to them. This walks through every line, in order, with the 2026 amounts.

Tax year 2026 · Updated 2026-08-29 · Guide

Step 1 — personal information and filing status

Name, address, Social Security number and filing status. Only the filing status has any effect on the arithmetic: it selects which withholding schedule applies.

Three options. Single or married filing separately. Married filing jointly or qualifying surviving spouse. Head of household, which is for unmarried people who pay more than half the cost of keeping up a home for a qualifying person — a genuinely more favourable schedule that many eligible single parents never select.

Steps 1 and 5 are the only mandatory ones. If you complete just those, your employer withholds as though your job is the household's only income and you take the standard deduction with no credits.

Step 2 — the most consequential box on the form

Complete this if you hold more than one job, or if you are married filing jointly and your spouse works. Skipping it is the single largest cause of an April balance due.

The reason is structural. The withholding tables build in the full standard deduction for your filing status. If two jobs each apply the full deduction, the household gets it twice — but the tax return only allows it once. On a joint return in 2026 that is a $32,200 phantom deduction applied twice, leaving thousands under-withheld.

You have three ways to fix it. 2(a) — use the IRS estimator at irs.gov/W4App, the most accurate route. 2(b) — use the Multiple Jobs Worksheet on page 3 and put the result on Step 4(c). 2(c) — check the box, and check it on the other job's W-4 too. The checkbox switches both jobs to a schedule with half-width brackets and removes the standard-deduction offset entirely, which is close to correct when the two jobs pay similarly and increasingly wrong as they diverge.

Rule of thumb: if the two incomes are within about 25% of each other, use the checkbox. If one job pays far more than the other, use the estimator or worksheet instead.

Step 3 — dependent and other credits

This asks for an annual dollar amount, not a number of children. For 2026: $2,200 for each qualifying child under 17 and $500 for each other dependent. Two young children is $4,400.

Payroll divides that total by your pay periods and subtracts it from each paycheck's computed withholding. It is floored at zero, so Step 3 can reduce withholding to nothing but never produce a negative.

In a two-earner household, only one spouse should claim the dependents. If both do, both payroll systems reduce withholding by the full amount and the household is short by the credit's value at filing. Convention is to claim them on the higher earner's W-4.

Step 4 — the three adjustment fields

4(a) Other income. Annual income with no withholding of its own — interest, dividends, retirement distributions, a side business. It is added to your annualized wages before the tables are applied, which raises withholding.

4(b) Deductions. Annual deductions beyond the standard amount. Subtracted from annualized wages, which lowers withholding. This is where the 2026 changes live. The redesigned Deductions Worksheet has new lines: 1a for qualified tips up to $25,000, 1b for qualified overtime up to $12,500 ($25,000 joint), 1c for qualified vehicle loan interest up to $10,000, and 3a and 3b for $6,000 each if you or your spouse are 65 or over. Line 6b caps state and local taxes at $40,400 ($20,200 if married filing separately). The worksheet total goes on Step 4(b).

4(c) Extra withholding. A flat dollar amount per paycheck, added after everything else. It is the bluntest and most reliable tool on the form, and the right way to close a known shortfall mid-year.

Step 5 — sign it

An unsigned W-4 is invalid, and an employer receiving one must withhold as though you were single with no adjustments. Date it. Your employer completes the employer section and must put the form into effect no later than the start of the first payroll period ending on or after the thirtieth day after you give it to them.

Claiming exempt

You may write 'Exempt' below Step 4(c) only if you had no federal income tax liability last year and expect none this year. It stops federal income tax withholding entirely — but not Social Security and Medicare, which are never affected by the W-4.

An exempt claim expires on 15 February of the following year and must be renewed. Claiming it when you do not qualify creates an underpayment and can attract penalties.

The five mistakes that cost the most

Leaving Step 2 blank with two incomes. The big one. Thousands under-withheld on a joint return.

Both spouses claiming the same dependents. Doubles the credit in withholding and halves your refund.

Treating Step 3 as a number of children. Entering '2' instead of '$4,400' reduces withholding by $2 a year instead of $4,400.

Expecting the 2026 tips and overtime deductions automatically. They are not in the tables. Without a Step 4(b) entry you get them as a refund, not a paycheck.

Never revisiting it. A W-4 filed at your first job in 2019 is still governing your withholding today.

Frequently asked questions

Related