A gross-up offset on your paycheck is a bookkeeping deduction that cancels out an equal amount your employer added to your gross wages, so the company can pay the taxes on a specific payment and still land your net deposit on the promised figure. You’ll see your gross pay inflated by the tax cost, then an “offset” line pulling that same inflation back out. No money leaves your pocket through the offset. It’s the accounting trick that lets your employer cover your tax tab on a bonus, a relocation payment, or a taxable fringe benefit.
What the Two Matching Lines Are Doing
When an employer promises a specific after-tax amount, they can’t just cut a check for that number. Every dollar of compensation triggers federal income tax, Social Security, Medicare, and often state or local withholding. Paying the target directly would shrink the deposit below what was promised.
The gross-up fixes that by calculating how much extra gross income is needed so that, after withholding, the net lands on the target. That extra amount gets added to your gross wages for the period. Your stub then shows an artificially high earnings figure, and right alongside it, an offset deduction of the same extra amount. Taxes are calculated on the full inflated gross. The offset removes the non-cash portion. What actually reaches your bank account is the original promised number.
A simplified example: your employer promises $1,000 after taxes. Payroll calculates that $1,300 in gross wages will produce exactly $1,000 after withholding. Your stub shows $1,300 in gross pay, taxes calculated on $1,300, and a $300 gross-up offset. You deposit $1,000. Your employer spent $1,300 to put $1,000 in your hands, and when the employer pays your share of Social Security and Medicare this way, the IRS treats that employer-paid tax as additional taxable wages you must report.1Internal Revenue Service. Publication 525 (2025), Taxable and Nontaxable Income
Why Employers Use It
Bonuses are the most common trigger. When a company announces a “$10,000 bonus,” leadership usually means the employee should see $10,000 in the bank, not $10,000 minus withholding. Grossing up makes the promise real.
Relocation packages are next. Employer-paid moving expense reimbursements are generally taxable income for non-military employees.2Internal Revenue Service. Moving Expenses To and From the United States If a company offers $8,000 to help you move, the gross-up ensures you actually have $8,000 available rather than losing a chunk to tax withholding.
Taxable fringe benefits round out the list. Personal use of a company car has a fair market value your employer must report as income. Certain awards, prizes, and gift cards also count as taxable compensation. In each case, the employer may gross up the value so you’re not writing a check to cover tax on something you never received as cash. The value of all taxable fringe benefits gets included in Box 1 of your W-2.3Internal Revenue Service. Publication 15-B (2026), Employers Tax Guide to Fringe Benefits
How the Extra Amount Is Calculated
The math is trickier than it looks, because the tax you’re trying to cover is itself calculated on the higher, grossed-up figure. Adding a flat tax percentage to the target doesn’t work: the added amount generates its own tax liability, which would need its own gross-up, and so on. Payroll systems use a reverse formula instead:
Gross Amount = Net Amount ÷ (1 – Combined Tax Rate)
The combined tax rate stacks every withholding that applies: federal income tax, Social Security (6.2%), Medicare (1.45%), and any state or local income tax.4Internal Revenue Service. Topic No. 751, Social Security and Medicare Withholding Rates The employee share of Social Security and Medicare alone totals 7.65% at minimum.
Pinning down an employee’s exact marginal federal rate mid-year is hard, so most employers use the flat 22% supplemental wage rate for bonuses and other one-time payments. The IRS allows the 22% rate for supplemental wages paid to an employee who has received less than $1 million in supplemental pay during the calendar year. Once supplemental wages cross $1 million, the excess must be withheld at 37%, regardless of what the W-4 says.5Internal Revenue Service. Publication 15 (2026), (Circular E), Employers Tax Guide
A Worked Example
Suppose your employer wants you to receive a $5,000 net bonus. Payroll assumes a combined tax rate of 35% (22% federal supplemental, 5.35% state, and 7.65% FICA):
$5,000 ÷ (1 – 0.35) = $5,000 ÷ 0.65 = $7,692.31
Your pay stub would show $7,692.31 in gross wages, roughly $2,692 in tax withholdings, and a gross-up offset of $2,692.31. You deposit $5,000.
What It Means for Your W-2 and Tax Return
The full grossed-up amount, not just the net you received, shows up in your W-2 wages and feeds directly into your adjusted gross income. This is real income the IRS expects you to report, even though the offset means the extra never touched your bank account. For most people receiving a grossed-up bonus of a few thousand dollars, the bump in AGI is too small to matter. For larger payments, the consequences can be meaningful.
Your AGI determines eligibility for a range of credits and deductions that phase out at certain income levels.6Internal Revenue Service. Definition of Adjusted Gross Income A substantial grossed-up relocation package or executive bonus could push you past a phase-out you’d otherwise clear, reducing your Child Tax Credit, education credits, or Roth IRA contribution eligibility. The gross-up covered withholding on the payment itself, but it can’t shield the rest of your return from AGI effects.
There’s a subtler risk too. When your employer uses the flat 22% supplemental rate but your actual marginal federal rate is 24% or higher, the withholding won’t fully cover your liability. You may not notice until you file and discover you owe. This happens most often in dual-income households or when a grossed-up payment lands late in the year after your income has climbed into a higher bracket. Checking your withholding after a large grossed-up payment is worth the five minutes.
Situations That Change the Math for You
The Social Security Wage Cap
The 6.2% Social Security tax only applies to earnings up to an annual cap. For 2026, that cap is $184,500.7Social Security Administration. 2026 Cost-of-Living Adjustment (COLA) Fact Sheet If your year-to-date wages already exceed that threshold when the grossed-up payment is processed, the 6.2% piece drops out of the formula. That lowers the combined rate and shrinks the gross-up amount. Payroll software usually handles this automatically, but it’s worth knowing if you’re a higher earner wondering why your gross-up offset looks smaller than a coworker’s on a similar bonus.
Additional Medicare Tax at Higher Incomes
An extra 0.9% Medicare tax kicks in once your wages pass $200,000 in a calendar year for employer withholding purposes, regardless of filing status.8Internal Revenue Service. Questions and Answers for the Additional Medicare Tax If the grossed-up payment pushes you past that line, the FICA share in the formula rises to 8.55% instead of 7.65%.
Overtime If You’re Hourly
If you’re non-exempt, a grossed-up bonus can create an overtime issue payroll sometimes misses. Under the Fair Labor Standards Act, nondiscretionary bonuses must be folded into your regular rate of pay when calculating overtime.9U.S. Department of Labor. Fact Sheet 56C: Bonuses Under the Fair Labor Standards Act (FLSA) The full grossed-up amount, not just the net target, is what enters that calculation. The bonus gets spread back over the workweeks during which it was earned, raising your regular hourly rate for each of those weeks.10eCFR. 29 CFR 778.209 – Method of Inclusion of Bonus in Regular Rate For any week you worked overtime during that period, you’re owed an additional half-time premium on the bonus portion. If your employer didn’t recalculate, you may have been underpaid.
If the Numbers Don’t Look Right
Gross-up errors happen more often than you’d expect, especially when payments are processed manually or the wrong tax rate goes into the formula. Common mistakes include using a flat combined rate that ignores state tax, failing to account for the Social Security wage cap, and running the gross-up at a point in the year when year-to-date income has shifted the effective rate.
If the gross-up is too low, your net falls short of what was promised. If it’s too high, your W-2 overstates your income and you’ve been over-withheld. Either way, the fix involves reversing the original entries, recalculating with the right inputs, and paying any shortfall. If the error isn’t caught until after the W-2 has been filed, the employer must issue a corrected Form W-2c to you and the Social Security Administration.11Internal Revenue Service. About Form W-2c, Corrected Wage and Tax Statements
Compare the net deposit to what your employer promised. Then check whether the gross-up amount divided by the net produces a ratio consistent with your combined tax rate. If the numbers don’t line up, raise it with payroll sooner rather than later. Corrections get messier the longer they sit, and messier still once a calendar year closes and tax forms have gone out.