Draft Form W-4 and how it impacts employers

Form W-4 (Employee's Withholding Certificate) is the IRS form that employees complete to instruct their employer how much federal income tax to withhold from each paycheck. The information provided on the W-4—including filing status, number of dependents, additional income sources, and any extra withholding amounts—determines the withholding calculation that employers apply using IRS tax tables or the percentage method worksheets. Employers are legally obligated to withhold the correct amount of federal income tax based on the employee's most current valid W-4; they cannot withhold a different amount without IRS authorization. If an employee fails to submit a W-4, employers must withhold as if the employee is single with no adjustments. Employers must retain completed W-4 forms for at least four years and make them available to the IRS upon request. When an employee submits a new W-4, employers must implement the change no later than the start of the first payroll period ending 30 days after the new form is received. Understanding the W-4 structure is essential for payroll professionals and HR staff responsible for accurate federal income tax withholding compliance.

The IRS significantly redesigned Form W-4 beginning with the 2020 version, eliminating the withholding allowance system that had been in place since 1987 following the Tax Cuts and Jobs Act's elimination of personal exemptions. The redesigned form uses a five-step process: Step 1 captures filing status and personal information; Step 2 addresses multiple jobs or a working spouse; Step 3 claims dependent tax credits; Step 4 captures other income, deductions, and additional withholding; and Step 5 is the signature. Only Steps 1 and 5 are required—employees without complex tax situations may submit a form with only these steps completed. The redesigned form is intended to be more accurate by using dollar amounts rather than allowances, better aligning withholding with actual tax liability. For employers, the change required updates to payroll systems and withholding calculation methods. Critically, employees who had a valid W-4 on file before 2020 are not required to submit a new form—employers continue using the old form until the employee submits an updated one. Training payroll staff and HR on the new calculation methods and advising employees on when to update their W-4 are key employer responsibilities under the redesigned system.

Employees should be encouraged to review and potentially update their Form W-4 whenever personal or financial circumstances change in ways that affect their tax liability. Major life events that commonly trigger a withholding review include marriage or divorce, the birth or adoption of a child, a change in employment status for the employee or spouse (including taking on a second job or a spouse starting or stopping work), a significant change in income from non-wage sources such as freelance work, investment income, or rental income, and major changes in deductions such as purchasing a home or large charitable giving. Employees who received an unexpectedly large tax refund or owed a significant amount when filing the prior year's return may also benefit from adjusting withholding to more closely match their actual liability. The IRS provides a Tax Withholding Estimator tool at IRS.gov that employees can use to calculate their appropriate withholding level. Employers and HR professionals can encourage periodic W-4 reviews without providing individual tax advice, particularly at the start of each year, when employees receive their W-2s, or following significant tax law changes. Proactively communicating when and how to update withholding helps employees avoid underpayment penalties and year-end tax surprises.

When an employee claims exempt status on Form W-4, they are certifying that they had no federal income tax liability in the prior year and expect none in the current year—allowing the employer to withhold zero federal income tax from their wages. Employers have specific obligations when exempt claims are received. They must implement the exempt withholding status as instructed, provided the form is properly completed and signed. However, employers are not required to accept a W-4 that appears fraudulent or claims an exempt status the employee clearly does not qualify for—in such cases, the employer should instruct the employee to complete a valid form and may notify the IRS. Exempt status is not permanent: it expires on February 15 of each year, after which the employer must revert to withholding based on single status with no adjustments unless the employee submits a new W-4 claiming continued exemption. Employers must retain all W-4 forms, including exempt claims, for at least four years. The IRS may issue a lock-in letter instructing an employer to withhold at a specific rate for an employee who has submitted questionable W-4 claims; employers who receive lock-in letters must follow them, even if the employee later submits a new W-4 showing lower withholding.

While the federal Form W-4 governs federal income tax withholding, state income tax withholding is governed by each state's own rules and forms, creating additional complexity for payroll professionals—particularly those managing employees in multiple states. Some states accept the federal W-4 as sufficient for state withholding purposes, but many states have their own withholding certificates with different calculation methods, allowances, or filing status options. A few states have no income tax and therefore require no state withholding. For employers with remote or multi-state employees, determining which state's withholding rules apply requires careful analysis of nexus and reciprocity agreements between states—many states have agreements that allow employees who live in one state but work in another to be taxed only by their home state. Payroll systems must be configured to apply the correct state withholding rules for each employee based on their work location, not the employer's headquarters. Failure to withhold correct state income taxes creates liability for both the employer and employee and may trigger state tax agency assessments. Staying current on state withholding form updates, tax rate changes, and withholding requirement changes for each jurisdiction where the organization has employees is an ongoing payroll compliance responsibility.