W-4 Tax Form

What is a W-4 tax form?

The IRS Form W-4, Employee's Withholding Certificate, is where your employee shares the personal and financial details you need to calculate their federal income tax withholding. Filing status, multiple jobs or a working spouse, number of dependents, additional income, and deductions all factor in, so the withholding matches each employee’s individual tax and financial needs.  

Your employee can use the IRS Tax Withholding Estimator to determine the right withholding amount before completing the form.  

Once you have the completed W-4, SurePayroll By Paychex stores that data and to calculate income tax withholdings each pay period.  

Read how to collect and process Form W-4.  

What is the purpose of the W-4 form?

The W-4 determines how much federal income tax to withhold from each paycheck. The amount affects your employee’s take-home pay and your tax compliance as the employer.  

For your employee, Form W-4 controls how much they take home each pay period. When they claim more credits and deductions, you withhold less tax, and their paycheck is larger. When they request extra withholding, their paycheck is smaller.  

The W-4 form also shapes your employee’s annual tax liability. Under-withholding triggers a tax bill and penalties at filing time. Over-withholding gives the government an interest-free loan.  

On the employer side, the IRS requires a signed W-4 on file for every employee. You use those details to calculate the federal withholding for each paycheck and deposit it with the IRS on schedule.  

At year end, you also use the W-4 information to prepare each employee’s IRS Form W-2, Wage and Tax Statement, which reports their total wages and taxes withheld.  

Who needs to file a W-4?

Every employee who receives wages from a U.S. employer must complete a Form W-4 when starting a new job. Full-time, part-time, and temporary employees all need one. Your employees should also file a new W-4 whenever their personal or financial circumstances change.  

Key changes to the W-4 form over time

2026  

Before 2026, the IRS deductions worksheet portion of Form W-4 was a short calculation: itemized deductions, the standard deduction, and adjustments like student loan interest. The 2026 version expanded to account for One Big Beautiful Bill Act changes: new lines for qualified tips, qualified overtime, and a senior deduction, each with its own income phase-out; a higher state and local taxes line; a new itemized-deductions limitation for higher earners; and updated standard deduction amounts for every filing status.  

Most of this affects how your employees calculate their own withholding and, eventually, their IRS Form 1040 Individual Income Tax Return. You don't need to walk them through it, but it's important to know that the worksheet changed. Employees can find the current W-4 and instructions on the IRS website.

2025  

Employees with tax-exempt qualified tips or overtime can adjust their withholding to account for that income. They use Step 4(b) on the W-4, along with the updated deductions worksheet, the IRS Tax Withholding Estimator, or a tax professional to set the right amount.  

Nearly 70 occupations now qualify for the No Tax on Tips provision under the One Big Beautiful Bill Act (Public Law 119-21). The list includes roles in food and beverage service, hospitality, gaming, entertainment, digital content creation, and rideshare driving. Employees in these roles can adjust their withholding to reflect the new deductions. They can update their W-4 at any time.  

2024  

The IRS updated tax brackets and standard deduction amounts in the form instructions and revised the deductions worksheet. No changes were made to the form itself or to federal withholding procedures. Employees with self-employment income, multiple jobs, or other tax situations can use the IRS Tax Withholding Estimator to calculate their withholding.  

2020  

The IRS redesigned the W-4 to simplify withholding calculations. The 2017 Tax Cuts and Jobs Act eliminated personal exemptions, so the redesigned form replaced the old "withholding allowances" system with income, dependent, and deduction fields. All employees hired after 2019 use the current version. If you or your employees left a job before 2020 and haven't filed a W-4 since, the form will look different now.  

What information is the W-4 asking about?

Each section focuses on a specific part of a person’s financial and family situation.  

• Step 1: Personal information. Your employee provides their name, Social Security number, and filing status based on marital status: single, married filing jointly, married filing separately, or head of household.  

• Step 2: Multiple jobs or spouse works. Your employee accounts for total household income when they have more than one job or a spouse who also works, often using the Multiple Jobs Worksheet to calculate the extra withholding needed.  

• Step 3: Dependents and tax credits. Your employee claims children and other dependents, along with eligible credits like the Child Tax Credit, which reduce withholding.  

• Step 4: Other adjustments. Your employee reports additional income not subject to withholding (freelance, investment income like dividends, retirement income, or other), itemized deductions beyond the standard deduction, and can request extra withholding here. The 2025 update to Step 4(b) lets them account for tax-exempt qualified tips and qualified overtime.  

• Step 5: Signature and date. Your employee signs and dates the form to make it valid.  

How to fill out a W-4 tax form (step-by-step)

Employees fill out the form in five steps:  

1. Provide their name, address, Social Security number, and filing status.  

2. Account for multiple jobs or a working spouse, so total household income is reflected correctly.  

3. Claim dependents and eligible tax credits.  

4. Include any other income or deductions to adjust withholding beyond the standard calculation.  

5. Sign and date the form before submitting it to you.  

Learn how to process a completed Form W-4 for your business.

You can also access the official IRS W-4 form and instructions (PDF).  

When is the W-4 usually completed?

You’re required to provide each new employee with a W-4 form when they’re hired. Use a paper form or an approved electronic system that meets IRS requirements.  

Your employee is responsible for completing the form correctly and submitting it to you, ideally before their first paycheck. If an employee doesn’t return a W-4, you must withhold federal income tax as if they’re single with no adjustments.  

Your employees should also review and update their W-4 whenever their personal or financial situation changes. Common examples include getting married, having a child, starting a second job, or gaining or losing a source of income.  

Your employees should review and update W-4 annually so withholding stays aligned with their actual tax liability.  

You'll use W-4 data each pay period for withholding, and again when filing quarterly Form 941 taxes.  

Common mistakes to avoid when completing a W-4

Errors on the W-4 affect your employee’s withholding. Five trouble spots are common:  

Forgetting to update the form after major life changes: Marriage, divorce, the birth of a child, or a new job all affect an employee’s tax situation. If your employee doesn’t update their W-4, the withholding may no longer match their financial reality.  

Leaving sections blank or incomplete: Each step affects the withholding calculation. If filing status, dependent details, or other information is missing, you withhold the wrong amount.  

Misunderstanding the multiple jobs section: If your employee or their spouse has more than one job, they need to complete Step 2 correctly. Overlooking this step may result in under-withholding and a tax bill at year’s end.  

Forgetting about additional income or deductions: If your employee earns money outside their main job (for example, freelance work or investments) and doesn’t account for it, they may owe more taxes when they file their tax return. Skipping deductions or credits may also result in excess withholding.  

Not signing or dating the form: Unsigned W-4s are invalid, so you can’t process them until your employee completes the form.  

Under-withholding may trigger a tax bill and penalties for your employee at filing time.  

Employer responsibilities with W-4 forms

The IRS requires you to retain employment tax records, including Forms W-4, for at least four years after the date the taxes were paid or became due, whichever is later. Store these forms securely, since they contain sensitive personal information.  

For electronic storage, use a reliable system that produces clear printed copies on request and includes strong passwords and security safeguards. Limit access to W-4 forms to authorized personnel, such as your human resources or payroll staff, who have a legitimate business need to view or handle the information.  

You’re responsible for entering each employee’s W-4 data into your payroll system. Verify the information to prevent payroll errors and maintain IRS compliance.  

SurePayroll® By Paychex stores W-4 data and applies withholding with every payroll run, minimizing manual entry and calculation errors.  

Update your payroll records promptly when an employee submits a new or updated W-4. You must begin using the revised withholding information no later than the first payroll period ending on or after the 30th day from when you receive the form.  

If an employee submits a W-4 that’s missing required information or contains obvious errors, return it for correction before applying the changes. Until they submit a valid form, you must calculate withholding as if the employee is single with no adjustments.  

What is the difference between a W-2 and a W-4 tax form?

A W-4 tells you how much to withhold; a W-2 reports what was actually withheld. Learn the key differences between W-2 and W-4 forms.  

A W-4 form is completed by your employee and tells you how much federal income tax to withhold from each paycheck.  

You prepare a W-2 form at the end of the current year to report an employee’s total wages and the taxes withheld for that tax year. You must provide W-2 forms to employees by the end of January each year, information your employees need to file Form 1040.  

Key takeaways

With each employee’s W-4 in hand, you withhold the correct federal income tax from every paycheck. Your employees complete it at hire and update it when their tax situation changes, and you apply that information each pay period to keep withholding aligned with their actual tax liability.  

Read our complete W-4 guide for step-by-step instructions  

Automate W-4 withholding calculations

SurePayroll calculates the withholding. You enter W-4 data once, run payroll, and the calculations stay consistent across every pay period. You keep control over timing and approvals while the system handles the calculations.  

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