What goes on each line of the W-4

The W-4 has six main sections. You fill in your name, address, and Social Security number at the top. Then you move through Step 1 (filing status), Step 2 (jobs and income), Step 3 (dependents), Step 4 (other income), and Step 5 (tax credits). Step 6 is where you sign. Most people only need to complete Steps 1, 3, and 6. The form takes 10 to 15 minutes if you have your documents ready.

Each section builds on the last. Your filing status (single, married, head of household) determines how much income is taxed at each rate. The number of dependents you claim reduces your taxable income. Other income and tax credits adjust what your employer withholds. If you skip a section that applies to you, your withholding will be wrong and you will either owe money at tax time or get a refund you did not need to wait for.

Key Takeaways

  • Line 1 asks for your name, address, and Social Security number — use the exact spelling on your Social Security card.
  • Step 1 requires you to choose your filing status (single, married filing jointly, married filing separately, or head of household), which determines your tax brackets.
  • Step 3 is where you list dependents — children and other relatives you support — because each one reduces the tax withheld from your paycheck.
  • If you have a spouse who also works, you both need to complete Step 2(c) to avoid over-withholding or under-withholding.
  • You must sign and date the form in Step 6 or your employer cannot process it.

Step 1: Filing status and personal information

Start at the top. Print your full name exactly as it appears on your Social Security card. If your name has changed since you got your card, update it with Social Security first — do not use a different spelling on the W-4. Write your address and Social Security number in the boxes provided. If you do not have a Social Security number, you cannot complete a W-4; you need an Individual Taxpayer Identification Number (ITIN) instead, which you get from the IRS.

In Step 1, check one box: single, married filing jointly, married filing separately, or head of household. Married filing jointly is the most common choice for married couples because it usually results in the lowest tax. Head of household applies if you are unmarried and pay more than half the household expenses for yourself and a dependent. Married filing separately is rare and usually costs more in taxes — only use it if a tax professional tells you to. Your filing status must match what you will file on your tax return in April.

Step 2: Handling multiple jobs and spouse income

Step 2 has three parts. Step 2(a) asks if you have more than one job. If you do, check "yes." Step 2(b) asks if your spouse works. If your spouse has a job and you file jointly, check "yes." Step 2(c) is the key: if you checked "yes" to either 2(a) or 2(b), you must use the IRS Multiple Jobs Worksheet (included with the form) to calculate how much extra withholding you need.

Why this matters: when you have two incomes, your employer does not know about the other one. Each employer withholds as if that job is your only income, which means you end up under-witholding. The worksheet tells you how much to add to your withholding to break even. If you skip this step and have two jobs, you will owe money in April. If both you and your spouse work, you can either both do the worksheet or have one spouse claim all the dependents and the other claim none — ask your employer's payroll office which method they prefer.

Step 3: Claiming dependents

A dependent is someone you support — usually a child under 17, a college student under 24 who you support, or a relative who lives with you and earns less than $4,700 per year (this number changes annually). For each dependent, write their name and Social Security number on the lines provided. Then check the box that describes them: child tax credit (most common for children), credit for other dependents (for adult relatives or older children), or both.

Each dependent you claim reduces your taxable income by a set amount. In 2024, each child under 17 reduces your withholding by roughly $2,000 for the year, spread across your paychecks. If you claim dependents you do not actually support, you will face penalties and interest when the IRS catches it. If you do not claim dependents you do support, you will over-withhold and get a refund. Only one person can claim each dependent on their taxes — if you and an ex-partner both have custody, you need to decide who claims the child, and only that person should list them on the W-4.

Step 4: Other income and deductions

Step 4 is for income that is not from a job — self-employment, rental income, dividends, or interest. If you have a side business or rental property, estimate how much you will earn this year and write it on line 4(a). If you have investment income, write that on line 4(b). These amounts affect how much your employer should withhold because they add to your total taxable income.

Line 4(c) is for deductions. Most people take the standard deduction (a flat amount the IRS sets each year). If you itemize deductions instead, subtract the standard deduction from your itemized total and write the difference here. For 2024, the standard deduction is $14,600 for single filers and $29,200 for married filing jointly — if your itemized deductions are less than these amounts, leave line 4(c) blank. This section is optional; most employees skip it and let the standard deduction handle their withholding.

Step 5: Tax credits and final adjustments

Step 5 is for tax credits — money the government gives you back, not just a reduction in taxable income. The most common are the Earned Income Tax Credit (EITC) and the Child Tax Credit. If you know you will receive credits, you can claim part of them now to increase your paycheck instead of waiting until April. Line 5(a) is for non-child tax credits. Line 5(b) is for the child tax credit. Line 5(c) lets you add extra withholding if you want — some people use this to ensure they do not owe money in April.

Most people leave Step 5 blank. If you are not sure whether you have tax credits, use the IRS Tax Credits Estimator on irs.gov. Claiming credits you do not have will result in a bill in April. If you claim them correctly, you either get a bigger refund or a larger paycheck throughout the year.

Step 6: Sign and date

At the bottom of the form, sign and date it. Your employer cannot process an unsigned W-4. Write the date you complete the form. If you are married and filing jointly, your spouse does not need to sign — only the employee signs. Once you sign, give the form to your payroll office or HR department. They will update your withholding in the payroll system, usually within one or two pay periods.

Keep a copy for your records. You do not file the W-4 with your tax return — it stays with your employer. If you change jobs, you need to fill out a new W-4 for the new employer. If your situation changes (you get married, have a child, or take a second job), fill out a new W-4 and submit it to your current employer.

Frequently Asked Questions

What if I do not know my Social Security number?

You cannot complete a W-4 without it. Contact Social Security at 1-800-772-1213 or visit ssa.gov to request a replacement card. Your employer cannot put you on payroll until you provide a valid Social Security number or ITIN.

Should I claim zero allowances to get a bigger refund?

The W-4 no longer uses "allowances" — that system ended in 2020. The current form uses steps and worksheets instead. If you want to over-withhold and get a refund, use line 5(c) to request extra withholding from each paycheck. Write the dollar amount you want withheld.

What happens if I give my employer the wrong W-4?

Your withholding will be incorrect. If you under-withhold, you will owe money in April plus interest. If you over-withhold, you will get a refund but lose the use of that money all year. You can submit a corrected W-4 at any time — your employer will adjust your withholding going forward.

Do I need to file a new W-4 every year?

No. Your W-4 stays in effect until you change it. You only need to submit a new one if your situation changes — marriage, divorce, a new job, a child, or a significant change in income. Some employers ask you to review it annually, but you only need to act if something is different.

Can my spouse and I both claim all the dependents?

No. Each dependent can only be claimed by one person on their tax return. If you both claim the same child, the IRS will reject one of the claims and you will face penalties. Decide together who will claim each dependent and make sure only that person lists them on their W-4.