Late in tax season, a familiar complaint starts showing up in payroll and tax-prep offices alike: an employee’s last pay stub of the year shows thousands of dollars in overtime pay, but the new box on the Form W-2 meant to report it for the tax deduction comes back at zero, or far lower than expected. Two years ago, the fix would have been simple — pull the pay stubs, calculate the number, and move on. For tax year 2026 and every year after it, the IRS has closed that shortcut.
Section 225(a) Requires the Number to Come From the W-2
The rule sits inside the same law that created the deduction. Under section 225(a) of the Internal Revenue Code, an employee can only deduct qualified overtime compensation that the employer actually included on a properly furnished Form W-2. The IRS’s fact sheet on the overtime deduction spells out what that means in practice: starting with tax year 2026, an employer must report an employee’s qualified overtime compensation on Form W-2 using the new box 12, code TT, and the return-time deduction is calculated from that reported figure, not from a worker’s own tally of extra hours. For tax year 2025 only, separate IRS guidance gave employers a pass on breaking the amount out and let workers calculate it themselves from pay stubs and payroll records; that transition relief does not carry into 2026 or any year after it.
Free retirement updates: Enrollment and claim windows come and go, and missing one can cost you real money. Our free Retirement Shield newsletter keeps readers ahead of the ones that matter. Get the free newsletter.
A Worker’s Own Overtime Log Doesn’t Count Anymore
The IRS is explicit that a detailed personal record isn’t a workaround. For tax years after 2025, the IRS fact sheet on the overtime deduction states that “employees may not consider any amount of qualified overtime compensation in excess of what is reported on Form(s) W-2, box 12, code TT” when figuring the deduction — even if the employee kept a precise log of every extra hour and can show, dollar for dollar, that the employer paid more. The guidance also closes a second door some workers might reach for: filing a substitute wage statement, Form 4852, in place of a missing or incomplete W-2. The IRS rules that out too, because section 225(a) requires the figure to come from a statement furnished under the specific tax code section that governs Form W-2, and a self-prepared substitute doesn’t meet that bar. The deduction is tied to the employer’s paperwork, not to the underlying pay itself.
Form W-2c Is the Only Fix the IRS Recognizes
When an employer under-reports the code TT figure, the burden falls on the worker to go back to that same employer. The IRS fact sheet states that an employee who reasonably believes the amount was omitted or understated “must request from the employer a Form W-2c…that properly reports the qualified overtime compensation using box 12, code TT” before the higher figure can be used on a return. Employers have their own reason to move quickly: the IRS’s general instructions for the 2026 Forms W-2 and W-3 note that the Form W-2c itself was updated in January 2026 to carry the new box, and an employer that files or furnishes an incorrect W-2 can face information-reporting penalties, with reduced penalties available only for prompt corrections.
What Happens If the Employer Won’t Correct It
The IRS fact sheet walks through both outcomes with side-by-side examples. In one, an employer that paid $10,000 in qualified overtime but reported only $5,000 issues a corrected W-2c after the employee flags the error, and the employee can then claim the full $10,000 on Schedule 1-A. In the other, the employer is unwilling or unable to issue the correction, and the employee is limited to the $5,000 that was actually reported — regardless of pay stubs, timesheets, or any other proof of the higher amount. That leaves a worker with one practical move: raise the discrepancy with payroll or human resources as soon as it turns up, in writing, and keep pressing for the corrected Form W-2c before filing, since nothing submitted afterward can substitute for it on the return.
Pay Stubs Still Matter, Just Not the Way They Used To
None of this means a worker’s own records are worthless — they just serve a different purpose than they used to, a shift the IRS had already signaled in its original overtime FAQ before the August 2026 update spelled out the correction process in detail. A pay stub or a personal log of overtime hours can’t be entered directly into Schedule 1-A anymore once the W-2 becomes the required source, but it’s still the evidence a worker needs to show payroll that an error exists in the first place. The overstatement side of the rule works the same way in reverse: if a Form W-2 reports more qualified overtime under code TT than the employer actually paid, the IRS says the employee may only claim the amount actually paid, not the inflated figure sitting in box 12. In practice, that means the smart move for a worker heading into filing season is to compare the box 12, code TT figure against a full year of pay stubs before ever touching Schedule 1-A, and to raise any mismatch with the employer immediately rather than waiting until a return is nearly finished. The earlier that conversation happens, the more time an employer has to issue a Form W-2c before a filing deadline forces the issue.
This article was produced with AI assistance and reviewed by a human editor. Figures are linked to their primary sources; where a claim could not be verified from the public record, we say so.
More Financial Reading
