Form W-4 & US Tax Withholding Guide
Understand how Form W-4 affects federal income-tax withholding and when employees should review it.
Quick answer
Form W-4 tells an employer how to calculate federal income-tax withholding. Review it after major life or income changes and use the IRS estimator when your situation involves multiple jobs, non-wage income, deductions or credits.
When to review your W-4
- You start or leave a job.
- Your filing status or family situation changes.
- You have more than one job or a working spouse.
- You receive significant non-wage income.
- Your prior refund or balance due was much larger than expected.
How the form works
The form considers filing status, multiple jobs, dependants, other income, deductions and any additional amount you request. Avoid copying last year’s entries without checking whether your circumstances changed.
Use the estimator carefully
The IRS Tax Withholding Estimator can help translate your year-to-date income and withholding into suggested W-4 entries. Recheck after submitting a new form by reviewing a later pay statement.
Keep these records
- A copy of the W-4 you submitted.
- Recent pay statements and year-to-date withholding.
- Income estimates for all jobs.
- Records of credits, deductions and non-wage income considered.
Educational information only: Rules and thresholds can change. Confirm current requirements with the relevant authority or a qualified professional before acting.
