What's the Difference Between a W-4 and a W-2?

A W-4 and a W-2 are both payroll-related tax forms, but they serve completely different purposes and are used at different times. A W-4 is the form you fill out when you start a new job to tell your employer how much federal income tax to withhold from each paycheck — you submit it to your employer, not to the IRS. A W-2 is the form your employer sends to you (and the IRS) each January, summarizing the wages you earned and the taxes withheld during the prior year. Your W-4 elections during the year determine how much is withheld; your W-2 reflects the result of those elections. If too little was withheld based on your W-4, you'll owe money when you file; if too much was withheld, you'll get a refund. You can update your W-4 at any time if your financial situation changes.