Form W-4 tells an employer how to calculate federal income tax withholding. Learn its five steps, when to update it, and why California uses Form DE 4.
Form W-4, Employee's Withholding Certificate, is the federal form an employee gives to an employer so the employer can calculate federal income tax withholding from wages. The form considers filing status, multiple jobs, dependents and credits, other income, deductions, and any requested extra withholding.
Form W-4 does not determine the employee's final tax liability. It changes how tax is prepaid through paychecks. The annual return later compares total tax with withholding, estimated payments, and credits to determine a refund or balance due.
| Step | Purpose |
|---|---|
| 1 | Personal information and anticipated filing status |
| 2 | Multiple jobs or a spouse who also works |
| 3 | Qualifying children, other dependents, and applicable credits |
| 4 | Other income, deductions, and extra withholding |
| 5 | Signature |
Some employees with a straightforward tax situation complete only Steps 1 and 5. Others need the estimator, multiple-jobs worksheet, or a coordinated approach with a spouse.
Employers combine the W-4 information with wages and the IRS withholding methods. Increasing credits or deductions entered on the form generally reduces federal withholding. Requesting an additional amount on Step 4(c) increases withholding.
Lower withholding increases take-home pay now but can increase the risk of a balance due. Higher withholding reduces take-home pay now and can increase an overpayment or refund. The best choice is not automatically the largest refund; it is a level that fits the taxpayer's expected liability and cash-flow preference.
Assume a married couple both work. Each employer sees only the wages it pays. If both spouses select married filing jointly but ignore Step 2, each payroll system may apply withholding as though its job were the household's only wage income. Combined withholding can be too low.
The couple may use the IRS estimator, complete the multiple-jobs worksheet, use the Step 2(c) checkbox when appropriate, or request additional withholding. The most accurate method depends on relative wages, credits, deductions, nonwage income, and the time remaining in the year.
Form W-4 is completed by the employee and kept by the employer to guide future federal withholding. It is generally not attached to the employee's tax return.
Form W-2 is prepared by the employer after year-end to report actual wages and withholding. A new W-4 changes future payroll; it does not rewrite earlier paychecks or an issued W-2.
The redesigned federal W-4 introduced in 2020 no longer uses the old personal-allowance system. Employees instead enter dollar amounts and other information in the applicable steps.
An old pre-2020 W-4 can sometimes remain in effect until the employee submits a new form, but a new hire or employee making a change uses the current form. Do not convert an old allowance count into a new W-4 entry without using current instructions.
Review withholding after:
Checking midyear leaves more pay periods to make a gradual adjustment.
Step 4 can account for certain other income, deductions, and extra withholding. Some taxpayers increase wage withholding to cover tax on self-employment, interest, dividends, capital gains, or a spouse's income.
This does not turn nonwage income into wages or eliminate separate reporting. It simply changes a payment source. Withholding is generally treated as paid evenly through the year for estimated-tax purposes, which can make a late-year adjustment useful in some circumstances. See also the estimated tax safe harbor and underpayment penalty rules.
Exemption is not a preference to have no tax withheld. The employee must meet the current form's conditions, generally involving no federal income tax liability in the prior year and an expectation of none in the current year. An exempt W-4 normally must be renewed for a later year under the applicable deadline.
Social Security and Medicare taxes generally still apply even when federal income tax withholding is exempt.
Federal Form W-4 controls federal income tax withholding. California uses Employee's Withholding Allowance Certificate Form DE 4 for California personal income tax withholding. Since 2020, new California hires and employees changing withholding generally submit both forms.
The California DE 4 still uses allowance concepts and California-specific worksheets. An accurate federal W-4 does not guarantee accurate California withholding because the forms and tax laws differ.
Heath Income Tax can estimate federal and California tax, review withholding against projected liability, and help identify a practical W-4 and DE 4 adjustment.
Does Form W-4 determine my refund?
It affects federal withholding, which affects the refund or balance due, but the complete return determines total tax.
Can I change my W-4 during the year?
Yes. Employees can generally submit a new form when circumstances or preferences change.
Should married spouses submit the same W-4?
Not necessarily. The forms should be coordinated using both jobs and the household's expected return.
Can I request a fixed extra amount?
Yes. Step 4(c) allows additional federal income tax withholding per pay period.
Does California use Form W-4?
California requires Form DE 4 for state personal income tax withholding; federal Form W-4 is for federal withholding.
The definitions and examples on this page are for informational purposes only and do not constitute tax advice. Tax laws change frequently and individual circumstances vary. Consult a qualified tax professional before making decisions based on this content.
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