W-4 Form: Extra Withholding, Exemptions, and Other Things Workers Need to Know

Starting a new job? Want to boost your tax refund? Don't want to make estimated tax payments? Then you ought to get familiar with IRS Form W-4.

pen laying on a W-4 form
(Image credit: Getty Images)

The W-4 form is used by new employees to provide their employer with the information needed to determine how much income tax should be withheld from their wages. That's the basic purpose of the W-4 form. And while simple in principle, it's important to get your paycheck withholding correct. Otherwise, you may be in for a big surprise when you file your next tax return.

But the IRS's W-4 form can be used for other reasons, too. For instance, if you have a side hustle and don't want to be bothered with estimated tax payments, then you can sign up for extra withholding using the W-4 form. Ditto if you receive other non-wage income during the year. You can also use the W-4 form to tweak the next year's tax refund.

When filling out a W-4 form, you'll be asked to include things like your expected filing status, family income from other jobs, number of dependents, and tax deductions you plan to claim. (Some employers offer electronic versions of the form.) Once your employer has the necessary information, the company will take it from there and do the necessary calculations. But to help make sure you get it right, here are 10 things every worker needs to know about the W-4 form. Take a look so you can tackle your next W-4 form with confidence.

William Neilson
Associate Tax Editor, Kiplinger.com

William joined Kiplinger in July 2021. Prior to this, William worked in the tax world for over 15 years. He spent time working at the IRS, the U.S. Tax Court, and several private law firms where he dealt with both individual and corporate clients. He has a B.A. in Journalism from the University of Georgia, a J.D. from the Loyola University College of Law, and an LL.M. in Taxation from the Northwestern School of Law.