W-4 for a New Job: What to Do on Day One

What happens if you don't fill it out

If you don't submit a W-4, your employer is legally required to withhold federal income tax as if you are Single with no adjustments, the highest possible withholding rate. You won't get penalized, but you'll get smaller paychecks than necessary until you submit a form.

The simplest approach for most new employees

For a straightforward situation, one job, no major side income, single or married with a stay-at-home spouse, here's what to do:

1. Step 1: Fill in your name, address, SSN, and check the correct filing status box
2. Step 2: Skip unless you have multiple jobs or your spouse also works
3. Step 3: Enter your dependent amounts if you have qualifying children or other dependents (and your income is under $200,000)
4. Step 4: Skip unless you have other income or deductions to account for
5. Step 5: Sign and date

If this is your only job and you're single

Fill in Step 1 with your information, select "Single or Married filing separately," skip Steps 2, 4, and sign Step 5. That's it. Your withholding will be calculated at the standard single rate and should come out approximately right at tax time.

If you're starting a job while keeping another job

You need to complete Step 2, otherwise each employer will withhold as if their job is your only income, and you'll likely be underwithheld when the incomes are combined. See our two jobs guide for the step-by-step process.

If you're newly married

Update your filing status to "Married filing jointly" in Step 1. If your spouse also works, complete Step 2 as well. See our married couples guide for full details.

Use the calculator for any complex situation

If your situation doesn't fit the simple cases above, our W-4 tool walks you through it step by step and tells you the exact amounts to enter.