Form W-4 Explained: How to Get Your Tax Withholding Right

Form W-4 might be the most important tax form you fill out at work, yet many people complete it quickly when starting a job and never think about it again. The W-4 tells your employer how much federal income tax to withhold from each paycheck, which directly affects your take-home pay and whether you’ll get a refund or owe money when you file your tax return.

Why withholding matters

The U.S. tax system is pay-as-you-go, meaning you’re generally expected to pay taxes throughout the year as you earn income. For employees, withholding from paychecks is how most of those payments are made.

Getting your withholding right matters because both too little and too much have downsides.

If too little is withheld, you may owe money when you file your tax return, and possibly penalties if you underpaid significantly during the year. A large unexpected tax bill can strain your budget.

If too much is withheld, you’ll get a refund when you file. While many people enjoy receiving a refund, it means you had less money in each paycheck during the year, essentially giving the government an interest-free loan. That money could have gone toward savings, debt payments or other goals throughout the year.

The goal for many people is to withhold close to the amount they’ll actually owe, avoiding both a large bill and an unnecessarily large refund. Some people prefer a modest refund as a cushion or a form of forced savings, which is a personal choice.

The W-4’s main steps

The current W-4 was redesigned in recent years and no longer uses withholding allowances. Instead, it uses a step-by-step approach.

Step 1 asks for your personal information and filing status, such as single, married filing jointly or head of household. Your filing status affects how much tax is withheld.

Step 2 addresses multiple jobs or a working spouse. If you have more than one job at the same time or you’re married filing jointly and your spouse also works, completing this step helps ensure enough tax is withheld based on your combined income. Without it, you may be underwithheld.

Step 3 lets you claim dependents and other credits, such as the Child Tax Credit and the credit for other dependents. Claiming these reduces your withholding to reflect credits you’ll receive when you file.

Step 4 covers other adjustments. You can enter other income not from jobs, such as interest, dividends or retirement income, to have tax withheld on it. You can enter deductions beyond the standard deduction if you expect to itemize. And you can request extra withholding, a specific additional amount withheld from each paycheck.

Step 5 is signing and dating the form.

Most people only need to complete the steps that apply to them. If you’re single with one job and no dependents, you may only need to complete Steps 1 and 5.

Use the IRS Tax Withholding Estimator

The IRS Tax Withholding Estimator, available free on irs.gov, walks you through your situation and suggests how to fill out your W-4. It considers your income, filing status, dependents, deductions, credits and other factors to estimate your tax liability and recommend withholding.

Have a recent pay stub and your most recent tax return handy when you use it, since it asks about your year-to-date earnings and withholding. If you’re married and both spouses work, have pay stubs for both.

When to update your W-4

Your W-4 stays in effect until you submit a new one, so it’s important to update it when your life changes. Consider updating your W-4 when you get married or divorced, have or adopt a child, start a second job or side hustle, when your spouse starts or stops working, when you experience a big change in income, such as a raise or reduced hours, or if you owed a lot or received a very large refund last year.

Reviewing your withholding once a year, perhaps early in the year or after filing your tax return, is a good habit, even if nothing major has changed.

Handling side income

If you have side income from freelancing, a side hustle or investments, no taxes are typically withheld from that income. You can make quarterly estimated tax payments to cover it. Alternatively, you can ask your employer to withhold extra on your W-4, using Step 4, to cover taxes on your side income instead of making separate estimated tax payments. Many people find increasing withholding simpler, though you’ll need to estimate how much extra to withhold.

Claiming exemption from withholding

In limited circumstances, you may be able to claim exemption from federal income tax withholding, such as if you had no tax liability last year and expect none this year. This is uncommon, and claiming exemption when you don’t qualify could result in a large tax bill. An exemption claim generally must be renewed each year.

State taxes

Your state may have its own withholding form, separate from the federal W-4, if it has a state income tax. Check with your employer or your state’s tax agency to make sure your state withholding is also correct.

Taking a few minutes to get your W-4 right can help you avoid surprises at tax time and make sure your paycheck works for your financial goals throughout the year.