Do Employees Need to Fill Out a W-4 Every Year?

No, employees generally do not need to fill out a W-4 every year. Once your employer has a completed Form W-4 on file, it controls your federal income tax withholding indefinitely, with no expiration date.¹ Three situations break that rule: starting a new job, claiming exemption from withholding, and receiving an IRS lock-in letter. Outside those, refiling is optional, though a review after any major life change is worth the ten minutes.

Your Existing W-4 Keeps Working

The W-4 has no built-in renewal clock. When the IRS redesigns the form, the redesign does not invalidate what you already submitted; your employer keeps withholding based on the last version you turned in. The IRS recommends that employees review their withholding each year, but a recommendation is not a requirement.¹ If your income, family, and filing status are steady, the form on file is doing its job.

When You Actually Have to Submit a New W-4

Starting a New Job

Every employer must have a W-4 for every employee, and a form filed with a previous employer does not transfer. You complete a new one during onboarding. If you skip it, your employer must withhold as though you are a single filer with no adjustments to Steps 2, 3, or 4, which typically pulls out the highest amount for your income.²

Claiming Exempt Status

Exemption from withholding is the one situation that truly does require an annual W-4. Exempt status expires each year, and the general deadline to refile and keep it is February 15.² For 2026, that date falls on a Sunday, so the deadline shifts to Monday, February 17, 2026.³ Miss it and your employer must start withholding at the default single-filer rate with no other adjustments.

Exempt status is only available if you had no federal tax liability last year and expect none this year. That limits it mostly to low-income workers and certain students. If your situation has changed and you no longer qualify, filing a new exempt W-4 anyway can trigger a $500 penalty.

An IRS Lock-In Letter

If the IRS decides your withholding is too low, it can send a lock-in letter directly to your employer. That letter overrides whatever W-4 you have on file and forces your employer to withhold at the rate the IRS sets.⁴ Your employer must put the lock-in rate into effect no sooner than 60 days after the date of the letter, which gives you a window to submit a new W-4 and a written explanation to the IRS address on the letter arguing for a lower rate.⁵

Once the lock-in takes effect, your employer must ignore any W-4 you submit that would decrease withholding. Only direct IRS approval can lower the rate.⁴ You can still file a W-4 that increases withholding above the lock-in figure. If you leave the job and come back within 12 months, the lock-in follows you.

Life Events Worth Updating For

Refiling stays optional in these situations, but ignoring a change usually means either a surprise tax bill in April or an interest-free loan to the government through excessive withholding. The IRS recommends a new form whenever your personal or financial situation shifts.⁶

Marriage or divorce. Filing status drives your standard deduction and tax bracket. For 2026, the standard deduction runs $16,100 for a single filer and $32,200 for married filing jointly, a large swing if your form still reflects the old status.⁷
A new child or dependent. Each qualifying child under 17 is worth up to $2,200 on the 2026 W-4, and other dependents qualify for $500, both of which reduce the tax withheld from each paycheck.⁶⁸
A spouse starting or leaving a job. Going from one income to two often lands the household in a higher bracket. Step 2 of the W-4 exists for this.
Significant non-wage income. Dividends, rental income, or investment gains that have no tax withheld at the source can leave you short at filing. Line 4(c) lets you request extra withholding to cover it.⁶
Buying a home or another shift in deductions. If itemized deductions now exceed the standard amount, Step 4(b) lets you account for that and pull your withholding down toward your real liability.

How to Submit an Update and When It Takes Effect

Give the new form to payroll or HR, or enter it through your employer’s electronic portal. Paper forms need a signature and date. Your employer must put the new withholding into effect no later than the start of the first payroll period ending on or after the 30th day from the date they received it, which usually means one or two pay cycles.²

If a life event happened mid-year, don’t wait for January. Submitting a revised W-4 in October to fix a change from March forces the correction into the last few paychecks of the year. Earlier is smoother.

What Getting It Wrong Costs

Under-withholding is not just an inconvenience at filing time. The IRS charges an underpayment penalty calculated at 7% annual interest, compounded daily as of early 2026, and it applies to each quarter you were short rather than the annual total.⁹

You avoid the penalty if your combined withholding and estimated payments meet either safe harbor:

90% of your current-year tax liability, or
100% of last year’s tax, taken from a return that covered a full 12 months.¹⁰

If your prior-year adjusted gross income exceeded $150,000 ($75,000 if married filing separately), that second threshold rises to 110% of last year’s tax.¹⁰ Higher earners coming off a big year often get caught here: withholding close to what they expect to owe this year still misses the 110% mark unless the 90% current-year test also holds.

On the other side, deliberately filing a W-4 that under-withholds carries its own cost. Claiming dependents you don’t have, filing exempt when you know you’ll owe, or otherwise providing false information carries a $500 civil penalty per false statement when the false information reduces withholding and you had no reasonable basis for the claim.¹¹ The IRS can waive it if your total tax for the year ends up covered by credits and payments, but that waiver is not something to plan around.

1
Internal Revenue Service. About Form W-4, Employee’s Withholding Certificate
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Internal Revenue Service. Topic No. 753, Form W-4, Employees Withholding Certificate
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Internal Revenue Service. Form W-4, Employee’s Withholding Certificate, 2025
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Internal Revenue Service. Understanding Your Letter 2800C
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Internal Revenue Service. Withholding Compliance Questions and Answers
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Internal Revenue Service. Form W-4 (2026) – Employee’s Withholding Certificate
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Internal Revenue Service. IRS Releases Tax Inflation Adjustments for Tax Year 2026, Including Amendments From the One, Big, Beautiful Bill
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Internal Revenue Service. Child Tax Credit
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Internal Revenue Service. Interest Rates Remain the Same for the First Quarter of 2026
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Office of the Law Revision Counsel. 26 USC 6654 – Failure by Individual to Pay Estimated Income Tax
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Office of the Law Revision Counsel. 26 USC 6682 – False Information With Respect to Withholding