What goes on each line of the W-4

The W-4 form has five main sections. Line 1 asks for your name, address, and Social Security number — copy these exactly as they appear on your Social Security card. Line 2 asks for your filing status: single, married filing jointly, married filing separately, or head of household. Line 3 is where you claim dependents — children under 17, and other relatives you support. Line 4 captures other income, like self-employment or investment earnings. Line 5 is where you account for a second job or spouse's income.

The form also includes Step 2, which is optional. This is where you adjust your withholding if you expect to owe money at tax time or want a larger refund. Most people leave this blank. Step 3 lets you claim dependents by name and age. Step 4 is for other income adjustments. Step 5 is for jobs held by you and your spouse, if both of you work.

You do not need to do math on the W-4 itself. The IRS provides a worksheet on the back of the form and an online calculator at irs.gov that walks you through each question. The worksheet takes about 10 minutes if you have your most recent tax return nearby.

Key Takeaways

  • Your name, address, and Social Security number on Line 1 must match your Social Security card exactly, or your employer cannot process the form.
  • Your filing status on Line 2 determines the base withholding amount, and changing it is one of the most common reasons to submit a new W-4.
  • Claiming dependents on Line 3 reduces the amount withheld from each paycheck, so only claim dependents you actually support.
  • The IRS withholding calculator at irs.gov accounts for multiple jobs, spouse income, and other earnings — using it takes 10 minutes and is more accurate than guessing.
  • You can submit a new W-4 to your employer at any time; you do not have to wait for a new job or the start of the year.

Line 1: Personal information and filing status

Start with your full legal name as it appears on your Social Security card. If you have changed your name since you got your card, update your Social Security record first — your employer's payroll system will flag a mismatch and delay processing. Your address should be your current mailing address. Your Social Security number goes in the box at the top right.

Line 2 is your filing status. This is the status you will use when you file your tax return in April, not your current marital status on the day you fill out the form. If you are married but file separately from your spouse, select "married filing separately." If you are single but support a child or parent, you may be able to claim "head of household" — the IRS worksheet will tell you if you may have access to. Your filing status directly affects how much is withheld, so getting this right matters more than the other lines.

Line 3: Claiming dependents

A dependent is someone you support financially and claim on your tax return. This usually means children under 17, but can also include adult children, parents, or siblings if you provide more than half their financial support. You list each dependent's name, age, and relationship to you. Do not guess at how many dependents to claim — only list people you actually will claim when you file your return in April.

Claiming a dependent reduces your withholding, which means a smaller amount comes out of each paycheck. If you claim a dependent you do not actually support, you will owe money at tax time. If you do not claim a dependent you do support, you will get a larger refund than you should have. Either way, the IRS will catch the mismatch when you file your return.

Lines 4 and 5: Other income and multiple jobs

Line 4 asks about other income: self-employment earnings, rental income, investment income, or a pension. If you have a second job or your spouse works, that goes on Line 5. These sections exist because withholding from a primary job alone does not account for total income. If you work two jobs and only fill out a W-4 at the first job, your withholding will be too low.

The worksheet on the back of the form walks you through how to adjust for multiple jobs. The simplest approach: if you and your spouse both work, one of you can claim all the dependents on that person's W-4, and the other person can claim zero. This spreads the withholding more evenly. Alternatively, use the IRS calculator, which handles this automatically.

Step 2: Adjusting withholding for other income or deductions

Step 2 is optional and most people skip it. It is for people who expect to owe money at tax time or want to adjust their refund. If you have significant investment income, rental income, or deductions that do not show up in your W-4 answers, you can enter an amount here to increase or decrease your withholding.

For example: if you have $5,000 in investment income that is not subject to withholding, you might enter $500 in Step 2 to have an extra $500 withheld across the year. Or if you know you will have large deductions, you might enter a negative number to reduce withholding. The worksheet on the back explains how to calculate this, but the IRS calculator is faster and more accurate.

Submitting your W-4 to your employer

Give the completed form to your employer's payroll or human resources department. Some employers accept W-4s online through their payroll portal; others want a printed copy. Ask your payroll contact which method they use. Your employer must process the form within a reasonable time — usually within one or two pay periods.

You can submit a new W-4 whenever your situation changes: after a marriage, divorce, birth of a child, or change in filing status. You do not have to wait for January 1 or a new job. If you submitted a W-4 that results in too much or too little withholding, submit a corrected one as soon as you notice the problem.

Common mistakes to avoid

The most common error is claiming too many dependents. If you claim dependents you do not actually support, your withholding will be too low and you will owe money in April. The second most common error is not updating your W-4 after a major life change — marriage, divorce, or a second job. Your withholding is based on the information in your most recent W-4, so old information leads to incorrect withholding.

Another frequent mistake is mismatching your name or Social Security number. If your W-4 says "John Smith" but your Social Security card says "John Michael Smith," payroll will flag it and may delay processing. A third mistake is leaving Line 2 blank. Your filing status is required, and payroll cannot process the form without it. If you are unsure of your filing status, the IRS worksheet or calculator will guide you through the options.

Frequently Asked Questions

Do I have to fill out a new W-4 every year?

No. Your W-4 stays in effect until you submit a new one. However, you should review it each year around tax time to see if your situation has changed — a new dependent, a second job, or a change in filing status. If nothing has changed, you do not need to do anything.

What if I do not know my filing status?

Your filing status is determined by your marital status on December 31 of the tax year and whether you support dependents. The IRS worksheet on the back of the W-4 walks through the options. If you are married, you can file jointly or separately. If you are single but support a child or parent, you may may have access to for head of household. The IRS calculator also shows which status applies to your situation.

Can I claim my spouse as a dependent?

No. You cannot claim your spouse as a dependent, even if you file jointly. You can only claim children, parents, siblings, or other relatives who meet the IRS definition of a dependent. If both you and your spouse work, each of you fills out your own W-4 based on your own income and dependents.

What happens if I claim zero dependents?

Claiming zero dependents means the maximum amount is withheld from your paycheck. This results in a larger refund when you file your return in April. Some people do this intentionally if they expect to owe money or want to force themselves to save. However, if you actually have dependents, claiming zero means you are giving the government an interest-free loan.

Can I change my W-4 in the middle of the year?

Yes. You can submit a new W-4 to your employer at any time. If you get married, have a child, or take a second job, submit an updated W-4 as soon as possible. Your employer will process it within one or two pay periods, and the new withholding will start on the next paycheck.