How to Change Your Tax Withholding

What tax withholding is and why you might change it

Tax withholding is the amount your employer takes from each paycheck and sends to the IRS on your behalf. You can adjust how much gets withheld — which changes how much you take home each week and how much you owe (or get back) when you file taxes in April.

You might change your withholding if you got married, had a child, took a second job, went back to school, or your life circumstances shifted in a way that changes your tax picture. You might also change it if you got a big refund last year (meaning too much was withheld) or owed money (meaning too little was withheld). The goal is to get as close as possible to zero — neither a large refund nor a bill.

Changing your withholding does not affect your actual tax bill. It only changes the timing: how much comes out now versus how much you settle up in April.

Key Takeaways

• You change withholding by filling out a new Form W-4 with your employer's payroll department, not by contacting the IRS.
• The IRS W-4 worksheet walks you through calculating the right withholding based on your income, dependents, and other jobs.
• Changes usually take effect on your next paycheck or within one or two pay periods.
• If you have a spouse who also works, you may need to coordinate withholding between both jobs to avoid underwithholding.

Getting and completing Form W-4

Form W-4 is the official IRS form that tells your employer how much to withhold. You can get it from your payroll department, download it from irs.gov, or ask your HR office to email it to you. The form itself is short — just one page — but it comes with a worksheet that helps you do the math.

The worksheet asks you to list your income from all jobs, count your dependents, and note whether you have a spouse who also works. It then walks you through calculating a number called your "allowances" or, on the newer version of the form, your "adjustments." This number is what you write on the actual W-4 that you give to your employer.

If you do not want to use the worksheet, you can also just write a number on the form — for example, "0" if you want maximum withholding, or a higher number if you want less withheld. Many people do this if their situation is straightforward (single, one job, no dependents).

When to file a new W-4

You should file a new W-4 whenever your life changes in a way that affects your taxes. Common times are: after you marry or divorce, when you have a child or adopt, when you take a second job, when your spouse starts or stops working, or when you claim a dependent for the first time.

You should also file a new W-4 if you got a refund of more than a few hundred dollars last year, or if you owed money. Both of those mean your withholding was off.

There is no penalty for changing your W-4 multiple times. If you are not sure whether your withholding is right, you can also use the IRS withholding calculator on irs.gov — it asks you questions about your situation and tells you what number to put on your W-4.

How to submit your new W-4 to your employer

Once you have filled out the form, give it to your payroll department or HR office. Some employers let you submit it online through their payroll system; others want a printed copy. Ask your payroll contact which method they prefer.

Tell them when you want the change to take effect — for example, "starting with my next paycheck" or "starting January 1st." Most employers process W-4 changes within one or two pay periods, though some may take longer if you submit it late in a pay cycle.

Keep a copy of the W-4 you submitted for your own records. You do not need to send anything to the IRS — your employer handles that.

What happens if you have multiple jobs

If you work more than one job, withholding gets trickier because each employer withholds based only on what you earn from them. If your combined income from both jobs is higher than either employer realizes, you might end up underwithholded — meaning you owe money in April instead of getting a refund.

The W-4 worksheet has a section for this. You list income from all jobs, and the worksheet tells you how to split the withholding between them. A common strategy is to have one employer withhold extra (by claiming fewer allowances or entering a dollar amount in the "extra withholding" line) to make up for the other job.

For example, if you work two part-time jobs that together add up to $50,000 a year, you might have your main job withhold normally and your second job withhold an extra $50 or $100 per paycheck to cover the gap.

Adjusting withholding if you have a spouse who works

If you are married and both you and your spouse work, you need to coordinate your withholding. The IRS assumes that if you are married, only one of you works — so if both of you claim standard withholding, you might end up underwithholded.

The W-4 has a checkbox for "married filing jointly with more than one job or spouse also works." Check this box, and the worksheet will adjust your calculation. You and your spouse do not have to do anything special together — you each fill out your own W-4 — but you should both check that box so the math accounts for both incomes.

If you want to be extra careful, you can also use the IRS withholding calculator together, or have one spouse claim fewer allowances to build in a safety margin.

Understanding the difference between allowances and dollar amounts

Older versions of Form W-4 used "allowances" or "exemptions" — a number that represented how much of your income was not subject to withholding. Newer versions (from 2020 onward) use a different approach: you enter dollar amounts for dependents, other income, and extra withholding.

If your employer is still using an old W-4, the worksheet will tell you how many allowances to claim. If you are using the current version, you will enter dollar amounts instead. Either way, the goal is the same: to tell your employer how much to withhold.

If you are not sure which version your employer uses, just ask payroll. They will give you the right form and can walk you through it if you get stuck.

Frequently Asked Questions

How long does it take for a withholding change to show up in my paycheck?

Most employers process W-4 changes within one or two pay periods. If you submit it early in a pay cycle, it might take effect on your very next check. If you submit it late in a pay cycle, it might not show up until the following pay period. Ask your payroll department for a timeline specific to your company.

What if I want to withhold extra money for taxes?

You can enter a dollar amount in the "extra withholding" line on Form W-4. For example, if you have self-employment income or investment income that is not subject to withholding, you can have your employer withhold an extra $25 or $50 per paycheck to cover it. This is a safe way to avoid owing money in April.

Do I need to contact the IRS to change my withholding?

No. You only contact your employer's payroll department. The IRS does not process W-4 changes — your employer does. You do not need to file anything with the IRS or call them.

Can I claim zero allowances to get the maximum withholding?

Yes. If you want the most money withheld from each paycheck, you can claim zero allowances (or enter zero dependents on the newer form). This is a safe choice if you are not sure what number to use, though it means you will likely get a refund in April.

What if I change my W-4 and my paycheck goes down too much?

You can file another W-4 right away to adjust it. There is no limit to how many times you can change your withholding. If your take-home pay dropped more than you expected, talk to payroll about what number would work better, or use the IRS withholding calculator to recalculate.