Definition
Withholding is the portion of your wages that your employer sends directly to the IRS (and your state tax authority) on your behalf before you ever see your paycheck. Each time you're paid, your employer deducts a calculated amount for federal income tax, Social Security, and Medicare — and remits those funds to the government.
The amount withheld for federal income tax is based on two things: your gross wages for the pay period and the instructions you provide on your W-4 form (filing status, credits claimed, and any additional adjustments). Over-withholding means the IRS holds your money until you file and claim a refund. Under-withholding means you'll owe a balance — and potentially an underpayment penalty — when you file your return.
How this affects your W-4
Your W-4 is the primary tool for controlling how much is withheld from each paycheck. Updating your filing status, claiming dependent credits in Step 3, or adding other income in Step 4a all change the withholding calculation your employer uses.
The goal is to match your total annual withholding as closely as possible to your actual tax liability — so you neither hand the IRS an interest-free loan nor face an April surprise.
See how withholding affects your withholding
Use the free W-4 calculator to calculate your exact withholding with your specific situation.
Open the W-4 Calculator →Related terms
W-4 Form
The IRS form employees submit to their employer to control how much federal tax is withheld.
Federal Income Tax
The progressive income tax the U.S. federal government levies on wages and other income.
Underpayment Penalty
An IRS penalty charged when you owe more than $1,000 and your withholding falls below safe harbor thresholds.