What goes on each line of the W-4

The W-4 form has six main sections, and most people fill out only the first three. Line 1 is your name, address, and Social Security number — the same information on your driver's license or Social Security card. Line 2 asks for your filing status: single, married filing jointly, married filing separately, head of household, or may have access to widow(er). Your filing status on the W-4 should match what you plan to report on your tax return.

Line 3 is where you claim dependents — children under 17, or other relatives you support who meet IRS rules. You enter the number of dependents, and your employer uses this to reduce the tax withheld from each paycheck. Line 4 is for other income: if you have a second job, rental income, or investment income, you report it here so your employer can withhold enough to cover all your tax liability, not just what this job generates.

Line 5 is for deductions you expect to claim on your tax return. Most people either claim the standard deduction (a fixed amount that depends on filing status) or itemize deductions. If you claim the standard deduction, you can enter that amount here to reduce withholding. Line 6 is for tax credits — the child tax credit, education credits, or other credits that reduce your tax bill directly. You can enter an estimate of the credits you expect to claim.

Key Takeaways

  • Your name, address, and Social Security number go on line 1, and your filing status on line 2 — these must match your tax return.
  • Line 3 is where you claim dependents, which lowers the tax withheld from each paycheck.
  • Lines 4, 5, and 6 are optional and used only if you have other income, expect large deductions, or will claim tax credits.
  • You can update your W-4 whenever your situation changes — marriage, divorce, a new child, or a second job — without waiting for the new year.
  • Your employer uses the W-4 only to calculate withholding; it does not change your actual tax liability or what you owe when you file.

When to claim dependents on line 3

You claim a dependent on line 3 if someone lives with you and you provide more than half their financial support. The most common dependents are children under 17, but you can also claim an adult child, parent, sibling, or other relative if they meet the IRS rules. Each dependent you claim reduces your withholding by a set amount per paycheck.

If you are married and both spouses work, you and your spouse should coordinate your W-4s so you do not both claim the same dependent. If you each claim the same child, you will both get the withholding reduction, and you will owe money when you file. One spouse can claim the child on their W-4, or you can split the dependent between your two forms — for example, one spouse claims one child and the other spouse claims the second child.

How to handle a second job or other income on line 4

If you work two jobs, your employer at each job withholds tax based only on the income from that job. If your combined income from both jobs pushes you into a higher tax bracket, you may not have enough withheld at either job alone. Line 4 lets you tell your primary employer about the other income so they can withhold more.

You can enter the total amount of income you expect from your second job, or you can use the IRS W-4 calculator (available on IRS.gov) to figure out how much extra withholding you need. The same applies if you have rental income, self-employment income, or investment income — you can enter an estimate on line 4 to increase withholding at your main job.

Using lines 5 and 6 for deductions and credits

Line 5 is for deductions. If you plan to itemize deductions on your tax return — meaning you list out mortgage interest, property taxes, charitable donations, and other expenses instead of taking the standard deduction — you can enter the amount by which your itemized deductions exceed the standard deduction. This reduces your withholding. If you claim the standard deduction, you can enter the standard deduction amount itself to reduce withholding, though most people leave this blank.

Line 6 is for tax credits you expect to claim. The child tax credit is the most common: it is worth up to $2,000 per child under 17. Other credits include the earned income tax credit (EITC), education credits, and the child and dependent care credit. You can enter the total value of credits you expect to claim, and your employer will reduce your withholding accordingly. If you are unsure of the amount, the IRS W-4 calculator can estimate it for you based on your situation.

Signing and submitting your W-4

Once you have filled out all the lines that explore to you, sign and date the form. Your employer's payroll department will keep the W-4 on file. You do not send it to the IRS — your employer uses it only to calculate how much tax to withhold from your paycheck.

You can submit a new W-4 to your employer at any time. If you get married, have a child, take a second job, or your tax situation changes, you can fill out a new form and give it to payroll. The new W-4 takes effect on the next paycheck after your employer receives it, though some employers may delay it by one pay period. There is no penalty for changing your W-4, and you can change it as many times as you need.

Common mistakes to avoid

The most common mistake is claiming too many dependents or too much withholding reduction on line 5 or 6. If you reduce your withholding too much, you may owe money when you file your tax return in April. The IRS W-4 calculator is designed to help you get withholding as close to correct as possible, so using it is worth the few minutes it takes.

Another mistake is not updating your W-4 when your situation changes. If you get married, have a child, or start a second job, your withholding may no longer be correct. A new W-4 takes just a few minutes to fill out and submit to payroll. Similarly, if you are married and both spouses claim the same dependent, you will both get the withholding reduction and end up owing money — coordinate with your spouse to avoid this.

Some people also confuse the W-4 with the tax return. The W-4 is only for withholding — it tells your employer how much tax to take out of each paycheck. Your actual tax liability and what you owe or are owed is determined when you file your tax return, usually in April. The W-4 is a tool to try to get your withholding close to your actual tax liability so you do not owe a large amount or get a large refund.

Frequently Asked Questions

What is the difference between a W-4 and a tax return?

The W-4 tells your employer how much tax to withhold from each paycheck. The tax return is what you file with the IRS in April to report your actual income and calculate what you owe or are owed. The W-4 is a withholding tool; the tax return is where your actual tax liability is determined.

Can I claim zero dependents on my W-4 even if I have children?

Yes, you can claim fewer dependents than you actually have, which increases your withholding. This means less money in each paycheck but a larger refund when you file. Some people do this if they want to save money or are unsure of their tax situation. However, claiming zero dependents when you have children means you are withholding more than necessary.

What happens if I do not fill out a W-4?

If you do not submit a W-4, your employer will withhold tax as if you are single with no dependents — the highest withholding rate. You should fill out a W-4 as soon as you start a job so your withholding is based on your actual situation, not the default.

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

No, your W-4 stays in effect until you change it. However, the IRS recommends reviewing your W-4 each year, especially if your situation has changed. You can use the IRS W-4 calculator on IRS.gov to check whether your current withholding is still correct.

Can my employer refuse to accept a new W-4?

No, your employer must accept a new W-4 from you. They may ask you to use their payroll system or a specific form, but they cannot refuse to update your withholding based on a valid W-4 you submit.