Why Is My Bonus Taxed So High? 22% Flat Rate vs Aggregate Method

You crushed your goals this year and your boss hands you a $10,000 bonus. You start mentally spending it—maybe a vacation, maybe paying off that credit card.

Then the direct deposit hits. It's for $5,800.

What happened? Why was your bonus taxed so aggressively compared to your normal paycheck?

The IRS considers bonuses to be Supplemental Wages. And supplemental wages are subject to special withholding rules that differ from your standard salary.

How the IRS Views Your Bonus

The IRS gives your employer two different methods for calculating the taxes on your bonus. Your employer gets to choose which method they use, and you generally don't get a say in the matter.

Method 1: The Flat Rate Method (The Most Common)

This is the easiest method for payroll departments, so it's the one most commonly used.

Under this method, the IRS mandates that your bonus is withheld at a flat 22% federal tax rate. (If your bonus is over $1 million, the amount over $1 million is withheld at 37%).

Keep in mind, that 22% is just the federal income tax. You still have to pay:

• FICA Taxes (Social Security & Medicare): 7.65%
• State Income Tax (Varies by state, often withheld at a higher supplemental rate too)

When you add 22% federal + 7.65% FICA + 5-8% State, you suddenly see why 35% to 40% of your bonus vanishes instantly.

Method 2: The Aggregate Method

Some payroll systems use the aggregate method. This method combines your bonus with your regular paycheck amount into one giant sum.

Then, the payroll software calculates the tax withholding as if that massive sum was your normal, everyday paycheck. Because the combined amount is so large, the software assumes you make an enormous salary and bumps you into a much higher federal tax bracket.

This method often results in even higher withholding than the 22% flat rate.

Will I Get That Money Back?

Here is the crucial thing to understand: Withholding is not the same as tax liability.

When you file your taxes in April, the IRS doesn't care if the money came from a salary or a bonus. They lump it all together as total income and tax it based on your actual, final tax bracket.

If your normal effective tax rate is only 12%, but your bonus was withheld at 22%, the IRS owes you the difference. You will get that money back in the form of a larger tax refund.

It feels painful when the bonus is paid out, but the math always corrects itself at tax time.

Can I Avoid the High Withholding?

Legally, no. Your employer is required to use one of the two withholding methods for supplemental wages. You cannot adjust your W-4 to avoid the 22% flat rate on a bonus.

However, if you know a massive bonus is coming and you know it will result in a huge refund next year, you could technically adjust your W-4 to withhold less from your regular paychecks for the remainder of the year to balance it out. (Just be careful—if you under-withhold too much, you could face IRS penalties).

To see exactly how much you'll take home from your next bonus under both methods, try our Bonus Tax Calculator.