What is Form W-4?

Form W-4 tells your employer how much federal income tax to withhold from your pay.

Your W-4 choices, such as filing status, dependents, and extra withholding, determine your federal income tax withholding each pay period.

If too much or too little is withheld, update your W-4 with your employer.

Where to find it on your paystub

Not printed as a line, but some stubs show your filing status or allowances near the top.

StubParse reads every line of a paystub, including this one, and checks the math adds up.