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 choose your filing status — single, married filing jointly, married filing separately, or head of household. This choice affects how much tax your employer withholds from each paycheck.

Lines 3 through 6 handle dependents and other income. Line 3 is for claiming dependents under age 17 (you enter the number, not names). Line 4 is for other dependents like adult children or parents you support. Line 5 covers other income — side jobs, rental property, or investment earnings. Line 6 is for deductions you plan to claim when you file your tax return in April.

The final section, Step 4, lets you request extra withholding if you want more tax taken out each pay period, or claim exemption from withholding if you had no tax liability last year and expect none this year. Most people leave this blank.

Key Takeaways

  • Your filing status on the W-4 determines your withholding rate — married filing jointly and single have different tax brackets.
  • You claim dependents by number only on line 3; you do not list names or Social Security numbers on the W-4 itself.
  • If you have a second job or your spouse works, you may need to adjust line 2c or request extra withholding on line 4(c) to avoid owing money at tax time.
  • You can change your W-4 whenever your situation changes — new job, marriage, divorce, or a child born — and your employer must process it within a reasonable time.
  • Claiming exemption from withholding means no federal tax comes out of your paycheck; this is only legal if you had zero tax liability last year and expect zero this year.

How to handle dependents and other income

Line 3 asks how many dependents you have under age 17. Enter only the number. A dependent is someone you claim on your tax return — usually your child, but can include a grandchild or foster child you support for the whole year. If you are unsure whether someone counts as your dependent, check the IRS rules before filling out the W-4, because the number you enter affects your withholding.

Line 4 is for other dependents — adult children, parents, or siblings you support. Again, enter the number. The tax benefit for these dependents is smaller than for children under 17, so the withholding adjustment is smaller.

Line 5 asks about other income. If you have a second job, run a side business, or receive rental income or investment earnings, enter the total amount you expect this year. Your employer uses this to adjust your withholding upward, because that income is also subject to federal tax.

Line 6 is for deductions. If you plan to itemize deductions when you file your return in April, or if you have large deductions like mortgage interest or charitable donations, you can enter an estimate here. This reduces your withholding. Most people leave this blank and take the standard deduction instead.

Adjusting withholding for multiple jobs or a working spouse

If you have two jobs, or you are married and both you and your spouse work, your combined income may push you into a higher tax bracket. Your employer does not know about your other income, so each job withholds as if it is your only income. This often results in underpayment — you owe money in April.

The W-4 has a worksheet to handle this. On line 2c, you can enter an amount to reduce your withholding at this job, which frees up money in your paycheck. But the math is tricky. A simpler approach: on line 4(c), request extra withholding — tell your employer to take out an additional dollar amount each pay period. This ensures you do not underpay.

If you are married filing jointly and only one spouse works, you do not need to adjust anything. If both work, each of you should complete a W-4. The spouse with the higher income should claim most or all of the dependents and deductions on their W-4, and the other spouse should request extra withholding or use the worksheet on line 2c.

When to claim exemption from withholding

Line 4(e) allows you to claim exemption from withholding. This means your employer stops taking federal tax out of your paycheck. You can only do this if two things are true: you had zero federal income tax liability last year (meaning you owed nothing when you filed), and you expect zero liability this year.

This exemption is most common for students with part-time jobs, or for people whose income is below the threshold where tax is required. If you claim exemption but then earn more than expected, you will owe the full amount in April with no cushion from withholding. The exemption expires on February 15 of the following year, so you must renew it annually if your situation has not changed.

Do not claim exemption unless you are certain you will owe no tax. If you are unsure, it is safer to let withholding happen and get a refund in April than to claim exemption and face a bill you cannot pay.

Filing status and how it affects your withholding

Your filing status on the W-4 is the status you expect to use when you file your tax return in April. The four options are single, married filing jointly, married filing separately, and head of household. Each has a different tax rate and withholding table.

Married filing jointly has the widest income brackets, so it usually results in the lowest withholding rate per dollar earned. Married filing separately has the narrowest brackets and the highest rate. Single and head of household fall in between. If you are married but file separately for tax reasons, you must select that status on your W-4, even though it means more tax withheld.

If your marital status changes during the year — you marry, divorce, or become widowed — you should update your W-4 as soon as possible. Your new status takes effect on the next paycheck after your employer processes the form.

What happens after you submit your W-4

You give your completed W-4 to your employer's payroll or human resources department. They enter the information into their system and adjust your withholding starting with your next paycheck. There is no approval process — your employer must honor what you submit, as long as it is a valid IRS form.

Keep a copy of your W-4 for your records. You do not send it to the IRS. The IRS only sees the information your employer reports on your annual W-2 form, which includes the total tax withheld.

If you need to make changes, fill out a new W-4 and submit it to payroll. You can change your W-4 as many times as you need — when you have a baby, get married, take a second job, or realize your withholding is too high or too low. Each new form replaces the previous one.

Common mistakes to avoid

The most common mistake is entering a number on line 3 that is too high. If you claim more dependents than you actually have, your withholding drops and you will owe money in April. Count carefully: only children under 17 who you claim on your tax return count here.

Another mistake is leaving line 5 blank when you have other income. If you work two jobs and only fill out a W-4 at one of them, that employer withholds based on that income alone. Your second job's withholding is also based on that income alone. Together, you underpay. Enter your expected other income on line 5 at your main job, or request extra withholding on line 4(c).

A third mistake is claiming exemption from withholding when you do not may have access to. If you earned any income last year and owed tax, or if you expect to earn enough this year to owe tax, do not claim exemption. The penalty for false exemption claims can include fines.

Frequently Asked Questions

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

No. Your W-4 stays in effect until you change it. However, the IRS recommends reviewing it each year, especially after major life changes like marriage, divorce, or the birth of a child. If your situation has not changed, you do not need to submit a new form.

What if I want to change my withholding mid-year?

Fill out a new W-4 and give it to payroll. The change takes effect on your next paycheck. You can adjust as many times as you need — there is no limit on how often you can update your W-4.

Can I claim my spouse as a dependent on my W-4?

No. You can only claim dependents under age 17 on line 3, or other dependents (not your spouse) on line 4. Your spouse is handled through your filing status, not as a dependent.

What if I do not know my expected income for the year?

Make your best estimate based on your hourly rate and expected hours, or your salary if you are salaried. You can always adjust later if your income changes. It is better to estimate and adjust than to leave the form incomplete.

Does my employer report my W-4 to the IRS?

Your employer does not send the W-4 itself to the IRS. They use the information to calculate withholding and report the total tax withheld on your W-2 form in January. The IRS matches your W-2 to your tax return when you file in April.