Federal Income Tax Withholding & the W-4
How Form W-4 elections affect federal income tax on each paycheck, and how Publication 15-T methods relate to your stub.
What federal withholding is
Federal income tax withholding is an estimate of income tax collected from each paycheck so employees are closer to their year-end tax liability. It is not the same as FICA.
Role of Form W-4
Employees complete Form W-4 to set filing status, multiple-jobs treatment (Step 2), dependents credit amount, other income, deductions, and extra withholding. Employers use those elections with IRS Publication 15-T methods.
Why two people with the same gross see different FIT
Different W-4 steps, pre-tax deductions, pay frequency, and supplemental wages all change the withholding result.
How to check your stub
Compare the federal income tax line to your expectations after any W-4 change. Use a paycheck estimator, then confirm with your payroll administrator if something looks wrong.
Frequently asked questions
Should I claim “exempt” from withholding?
Only if you meet IRS exemption criteria. Incorrect exempt claims can lead to tax bills and penalties.
Do bonuses use a different federal method?
Employers may use supplemental wage withholding methods described by the IRS, which can look higher or lower than regular wages for a single check.
Sources
See also our full sources list, methodology, and editorial standards. This page is educational and not tax, legal, or accounting advice.
Put the numbers on a real stub
Preview federal, FICA, and state amounts with your own pay details.