Form W-4 Explained: A Step-by-Step Guide
Form W-4, the Employee’s Withholding Certificate, is how you tell your employer how much federal income tax to take from each paycheck. It is easy to fill out carelessly, and mistakes are expensive: too little withholding leads to a bill and possibly a penalty, and too much means you lend the government money interest-free. This guide goes through each step of the current form, with notes on when the simple answer is right and when you need to do more.
What the W-4 actually does
The W-4 does not set your tax. It feeds your employer’s payroll system, which applies the IRS withholding method described in Publication 15-T. Your actual tax is determined later on Form 1040. The W-4’s job is to make the two numbers close. You file it when you start a job, and you can submit a new one at any time. Your employer cannot tell you what to enter and does not send the form to the IRS unless asked.
Since 2020 the form no longer uses "allowances." If you filed an older version, your employer may still be using it, but you can submit the new version anytime to make your withholding match your situation.
Step 1: Personal information and filing status
Enter your name, address, Social Security number and filing status. Choose Single or Married filing separately, Married filing jointly (or qualifying surviving spouse) or Head of household. Your choice determines the standard deduction and tax brackets assumed in your withholding. For 2026, the standard deduction is $16,100 for single, $32,200 for married filing jointly and $24,150 for head of household. Head of household requires that you are unmarried and pay more than half the cost of keeping up a home for a qualifying person.
Steps 1 and 5 (signature) are the only required parts. If your situation is simple, one job, no other income, no dependents, you can stop after Step 1 and sign.
Step 2: Multiple jobs or a working spouse
This is the step most people get wrong. Each employer withholds as though that job is your only income, so each applies the lower brackets and the full standard deduction. If you or your spouse have more than one job, the combined withholding will typically be too low. You have three options:
- Use the IRS Tax Withholding Estimator (the most accurate option). The estimator uses your paystubs and returns a set of W-4 entries.
- Use the Multiple Jobs Worksheet on page 3 of the form, then enter the result in Step 4(c) on the highest-paying job’s W-4.
- Check the box in Step 2(c) if there are exactly two jobs (or you and your spouse each work one job) and the pay is roughly similar. This works best when both jobs pay about the same, and you must check it on both W-4s.
Checking the box makes withholding higher, since it uses the tables as if each person’s wages were stacked on top of the other’s. It is the most common way couples with similar incomes avoid a surprise at tax time.
Step 3: Claim dependents
If your income is below $200,000 ($400,000 for married filing jointly), you can reduce withholding for the child tax credit and other credits. Multiply your qualifying children under age 17 by $2,200 (the 2026 child tax credit), and multiply other dependents by $500. Enter the total in Step 3. Higher earners can still claim but the credit is reduced above those income levels, so withholding would be too low.
If two spouses both work, claim the dependents on only one W-4, otherwise both employers will reduce withholding for the same children.
Step 4: Other adjustments (optional)
4(a) Other income
Use this if you have income that has no withholding, such as interest, dividends, retirement income or a side business. Entering the expected annual amount increases withholding, so you may not need to make separate quarterly payments. Do not include self-employment income if you pay estimated tax; the estimated tax guide covers that approach.
4(b) Deductions
If you expect to itemize and your deductions will exceed the standard deduction, use the Deductions Worksheet and enter the excess here. This reduces withholding. Most taxpayers take the standard deduction and leave this blank.
4(c) Extra withholding
Enter a dollar amount you want withheld from every paycheck beyond the calculated amount. It is a simple tool for fixing a shortfall: if you expect to owe $1,200 and have 24 paychecks left, enter $50. It is also the easiest way to cover tax on bonuses or on a side income.
Step 5: Sign
An unsigned W-4 is invalid. Your employer will keep the form with its payroll records. Do not send it to the IRS.
Claiming exempt
You may write "Exempt" below Step 4(c) only if you meet both tests: you had no federal income tax liability last year, and you expect none this year. This is not the same as having a refund; it means your total tax was zero. An exemption lasts only until February 15 of the following year, so you must file a new W-4 each year to continue. Exempt status does not affect Social Security or Medicare tax; those are still withheld. Claiming exempt incorrectly can lead to a large bill and penalties.
Example: how W-4 choices change a paycheck
A single worker in Ohio earning $60,000, paid biweekly, with no deductions has estimated federal income tax of $5,020 a year, about $193.08 per check. If the same person adds $100 in Step 4(c), that is $2,600 extra over 26 paychecks, raising federal withholding to roughly $7,620 for the year and dropping net pay by $100 each check. A married couple that both work should compare options in the paycheck calculator, which shows estimated federal tax by filing status, children and other deductions.
Common W-4 scenarios
Single, one job, no dependents
Fill out Step 1, sign in Step 5 and you are done. Withholding will closely match your actual tax unless you have significant other income.
Married, both spouses working
Each spouse should check the Step 2(c) box if the jobs pay about the same, or use the estimator if they do not. Claim children on one W-4 only. Without this step, a typical two-earner couple under-withholds because each employer applies the full married-filing-jointly standard deduction and the lower brackets.
One main job plus a side business
Self-employment income has no withholding. You can raise your W-2 withholding using 4(c) or make quarterly estimated payments. A raised W-4 is simpler because withholding is treated as paid evenly throughout the year, even if the extra amount is increased late in the year, while estimated payments must meet their due dates to avoid penalties.
Starting a job mid-year
Your employer annualizes pay as if you earned your paycheck all year. If you were unemployed for part of the year, withholding may be higher than needed. Your return will reconcile it, but you can also use the estimator to adjust.
What your employer cannot do
Employers must follow the W-4 you give them. They cannot decide your filing status or refuse to apply a valid form because they think you should withhold more or less. The exception is a form the IRS has directed them to override in a lock-in letter, which is rare. If an employer refuses a signed, valid W-4, you can contact the IRS.
When to submit a new W-4
- You started a second job, or your spouse started or left a job.
- You got married, divorced or had a child.
- Your income changed significantly (a raise or a bonus program).
- You owed a large amount, or received a very large refund, when you filed your last return.
- Your side income or investment income grew.
Checking in the fall gives you time to correct a shortfall across the remaining paychecks. The withholding overview explains the mechanics behind these entries, and the bonus tax calculator shows how extra withholding interacts with one-time payments.