Workers who receive a bonus this year will see the IRS take a flat 22 percent cut before the money reaches their bank accounts. That withholding rate, applied automatically by most employers, often exceeds what an employee actually owes in federal income tax, shrinking the check and leaving the difference locked up until tax-filing season the following year. The gap between what is withheld and what is truly owed creates a quiet, recurring cost for millions of wage earners.
Why the flat 22 percent rate hits paychecks harder than expected
Federal regulations classify bonuses as supplemental wages, a category that carries its own withholding rules separate from regular pay. Under the optional flat-rate method described in IRS guidance, employers can withhold exactly 22 percent on a bonus payment without factoring in the worker’s W-4 elections, filing status, or number of allowances. For someone whose effective federal tax rate falls well below 22 percent, the result is immediate over-withholding that reduces take-home pay by hundreds or even thousands of dollars on a single bonus.
Employers gravitate toward this approach because it is simpler to execute. The alternative, known as the aggregate method, requires the payroll system to combine the bonus with the employee’s regular wages for that pay period, then recalculate withholding using the standard tables laid out in Publication 15-T, and finally separate out the additional amount. That process demands more computation per payroll run and greater attention to each worker’s current withholding elections. The flat-rate method, by contrast, applies one percentage to one number and moves on. The trade-off falls on the worker: any excess withholding is returned only as part of a refund after filing the next year’s return.
The 22 percent rate itself dates to 2018. Before that, the flat rate on supplemental wages stood at 25 percent for over a decade, a figure set for the years 2005 through 2017 according to the Internal Revenue Bulletin. The reduction to 22 percent tracked changes in the broader individual income tax brackets, but for workers in the 10 or 12 percent brackets, even 22 percent represents a significant over-collection on bonus income. Someone whose overall income would normally be taxed at a much lower average rate can still see nearly a quarter of a one-time payment siphoned off upfront.
IRS rules and regulatory text behind bonus withholding
The legal authority for treating bonuses this way sits in 26 CFR Section 31.3402(g)-1, which defines supplemental wage payments and explicitly lists bonuses among them. The regulation gives employers the option to apply the flat percentage method whenever a bonus is separately stated from regular wages. No additional approval or employee consent is required. The employer simply withholds 22 percent, remits it to the Treasury, and reports the amount on the worker’s W-2 at year end.
For employers that choose not to use the flat rate, the aggregate method effectively treats the bonus as if it were part of a larger regular paycheck. The payroll system adds the bonus to that period’s wages, looks up the total in the withholding tables, and withholds as though the combined amount were the worker’s ongoing pay. The extra tax attributed to the bonus is the difference between the new withholding figure and what would have been withheld on regular wages alone. This approach can produce withholding closer to what the employee will ultimately owe, but it is more complex for payroll departments to administer consistently.
A separate threshold applies to high earners. When an employee’s total supplemental wages exceed $1 million in a single calendar year, the withholding rate on the amount above that line jumps to 37 percent, according to the same IRS rules that govern supplemental wages. That higher rate mirrors the top individual income tax bracket and is mandatory rather than optional, meaning employers cannot choose a lower rate for the excess portion. For executives or highly compensated professionals whose bonuses cross that mark, more than a third of each additional dollar is withheld immediately.
What workers still cannot change about bonus taxes
Workers have little direct control over how their employer withholds tax from a bonus. The choice between the flat-rate and aggregate methods rests entirely with the payroll department, and federal regulations do not require companies to offer alternatives. An employee cannot opt out of the 22 percent rate for a separately stated bonus, nor can they insist that the employer recalculate withholding using the aggregate method instead.
Changing the information on a Form W-4 also has limited impact on a flat-rate bonus. Because the 22 percent method ignores filing status and other elections, updating a W-4 just before a payout will not lower the percentage withheld from the bonus itself. Any adjustment would only affect withholding on regular wages. For workers who know a bonus is coming and worry about cash flow, that constraint can be frustrating.
The underlying tax liability, however, is determined on the annual return, not by the withholding method. If the 22 percent rate causes too much tax to be collected on a bonus, the excess is reconciled when the worker files a return for the year. At that point, over-withholding contributes to a larger refund or reduces any balance due. The cost to the worker is the time value of money: funds that could have been used or invested throughout the year instead sit with the Treasury interest-free.
That timing gap is baked into the system as long as bonuses remain categorized as supplemental wages with a fixed withholding percentage. Unless Congress or the Treasury Department revises the rules, workers will continue to see sizable slices of their one-time payments diverted at 22 percent, with any correction arriving only after they navigate the annual filing process.
Warren Cohen is a finance writer based in Phoenix, Arizona, covering personal finance topics including credit, banking, and beginner investing. He earned his degree in business administration from Arizona State University and began his career working in consumer finance, where he gained direct experience with lending and credit systems. He now writes for personal finance websites and fintech platforms, focusing on clear, practical content that helps readers make informed financial decisions.
