What goes on each line of the W-4

The W-4 form has five main sections where you enter information. Line 1 asks for your full name, address, and Social Security number — this is how your employer matches the form to your payroll record. Line 2 asks for your filing status: Single, Married Filing Jointly, Married Filing Separately, or Head of Household. Choose the status you will use on your tax return.

Line 3 is where you claim dependents — children under 17, or other relatives who live with you and meet IRS rules. You enter the number of dependents, and the IRS provides a dollar amount per dependent that reduces your withholding. Line 4 covers other income: if you have a second job, rental income, or self-employment income, you report it here so your employer can withhold enough tax across all your income sources.

Line 5 is for tax credits other than dependents — things like the Child and Dependent Care Credit or the Earned Income Tax Credit. This section is optional; most people leave it blank. Line 6 lets you request extra withholding if you want more tax taken from each paycheck, or claim you are exempt from withholding if you had no tax liability last year and expect none this year.

Key Takeaways

  • Your filing status on the W-4 must match the status you will use on your tax return, or your withholding will be wrong.
  • Dependents reduce your withholding, so claiming them lowers the amount your employer takes out each paycheck.
  • If you have more than one job or other income, report it on Line 4 so your total withholding covers all your earnings.
  • You can request extra withholding on Line 6 if you want more tax taken out, or claim exemption if you owe nothing and expect to owe nothing.
  • You must sign and date the form; an unsigned W-4 is not valid and your employer may not process it.

Gathering information before you start

Before you sit down to fill out the form, collect a few documents. You will need your Social Security number and your spouse's Social Security number if you are married. Have your most recent tax return nearby — it shows your filing status and how many dependents you claimed last year, which is usually the same this year.

If you have a second job or self-employment income, write down the total you expect to earn from that source this year. If you are claiming tax credits, gather the documents that support them — for example, if you claim the Child and Dependent Care Credit, you will need the name and tax ID of the daycare provider. You do not need to attach these documents to the W-4, but having them on hand helps you fill out the form accurately.

How to handle multiple jobs or side income

If you work more than one job, your withholding can fall short because each employer withholds based only on the income from that job. The IRS W-4 form includes a worksheet to help you calculate how much extra withholding you need at your main job to cover tax on all your income.

On Line 4, you report income from your other jobs. The worksheet then tells you how much to enter on Line 6 (extra withholding) to make up the difference. For example, if your main job pays $40,000 and your second job pays $15,000, your main employer might withhold as if you earn only $40,000. The worksheet helps you request enough extra withholding to cover tax on the full $55,000.

Self-employment income works the same way. Report the amount you expect to earn on Line 4, and use the worksheet to calculate extra withholding at your W-2 job. This is simpler than trying to make quarterly estimated tax payments on your own.

Claiming dependents and tax credits

On Line 3, you enter the number of dependents you claim. The IRS defines a dependent as someone who lives with you for the whole year, is a relative (or meets other rules), and has income below a certain threshold. Children under 17 are the most common dependents. You can also claim adult children, parents, or siblings if they meet the rules.

Each dependent you claim reduces your withholding by a set dollar amount per year — the IRS updates this amount annually. If you claim three dependents, your employer withholds less from each paycheck than if you claim one. This is because dependents lower your tax bill, so you do not need as much withheld.

Line 5 is for other tax credits — not dependents. The most common are the Child and Dependent Care Credit (if you pay for childcare so you can work) and the Earned Income Tax Credit (if your income is below certain limits). These credits also reduce your tax bill, so claiming them on the W-4 lowers your withholding. Most people leave Line 5 blank and claim these credits when they file their tax return instead.

Requesting extra withholding or claiming exemption

Line 6 has two purposes. First, you can request extra withholding — an additional dollar amount your employer takes from each paycheck. This is useful if you know you will owe tax at the end of the year, or if you want a refund instead of owing. For example, if you have investment income or a spouse who does not work, you might request an extra $50 or $100 per paycheck.

Second, Line 6 is where you claim exemption from withholding. You can only do this if two things are true: you had no tax liability last year (you owed zero federal income tax), and you expect to have no tax liability this year. If you claim exemption, your employer will not withhold any federal income tax from your paycheck. This is rare and usually applies only to students or people with very low income.

If you claim exemption, you must renew it every year — the exemption expires on February 15 of the following year. If you do not renew it, your employer will treat you as Single with no dependents starting March 1.

When and how to submit your W-4

You fill out a new W-4 when you start a job — your employer will ask for it on your first day. You can also submit a new W-4 anytime you want to change your withholding. Common reasons to change it are: you get married or divorced, you have a child, you take a second job, or you realize your withholding is too high or too low.

Give the completed, signed, and dated form to your HR or payroll department. Some employers let you submit it electronically through a payroll portal; others want a paper copy. Ask your employer which method they use. Your new withholding takes effect on the first paycheck after your employer receives and processes the form — usually within one or two pay periods.

Keep a copy of your W-4 for your records. You do not file it with your tax return, but it is useful to have if you need to remember what you claimed or if the IRS asks questions about your withholding.

Common mistakes to avoid

The most common mistake is claiming the wrong filing status. If you are married but claim Single, your withholding will be too high. If you are single but claim Married, your withholding will be too low and you may owe tax. Check your status against your tax return to make sure it matches.

Another mistake is forgetting to update your W-4 when your life changes. If you have a child but do not add them as a dependent on your W-4, you will have too much withheld and get a large refund — money you could have used throughout the year. Similarly, if you get a second job but do not report it on Line 4, you may owe tax at the end of the year.

A third mistake is claiming exemption when you do not may have access to. If you claim exemption but you actually owe tax, you will owe it all at once when you file your return, plus interest and penalties. Only claim exemption if you are certain you will have no tax liability.

Frequently Asked Questions

What if I do not know my filing status yet?

Use your current status as of January 1 of the tax year. If you are single now but plan to marry later in the year, you can still claim Married on your W-4 starting the month you marry — just submit a new form to your employer. If you are unsure, claim Single; you can always adjust it later.

Do I have to claim all my dependents on my W-4?

No. Claiming dependents on your W-4 lowers your withholding. If you want more tax withheld, you can claim fewer dependents than you actually have, or claim none at all. You will claim the correct number when you file your tax return and get any refund you are owed.

What happens if I claim exemption but then earn more money than expected?

If you claimed exemption and your income rises above the threshold, you will owe tax when you file your return. You should submit a new W-4 right away to start withholding. The sooner you do, the smaller your tax bill will be.

Can my employer refuse to process my W-4?

Your employer must process a valid W-4 — one that is signed, dated, and filled out completely. If you leave required fields blank or do not sign it, they may ask you to correct it. If you claim exemption, your employer may ask you to confirm you meet the requirements, but they cannot refuse a valid exemption claim.

How often should I review my W-4?

Review it once a year, around the time you file your tax return. If you got a large refund, you are having too much withheld — consider claiming more dependents or requesting less extra withholding. If you owed tax, you are not having enough withheld — claim fewer dependents or request more extra withholding.