ILLINOIS BONUS TAX · TAX YEAR 2026
Illinois bonus tax calculator
Illinois has no separate bonus tax rate: a bonus is withheld at the state's flat 4.95% income tax rate, like any other wages. On a $10,000 bonus with $75,000 of wages, a single filer has $495 of Illinois tax withheld, plus $2,200 of federal income tax and $765 of Social Security and Medicare, and takes home $6,540. The bonus adds $495 to the year's Illinois tax, so withholding matches the tax.
Your bonus after tax
- Take-home bonus
- $6,540.00
- Federal income tax
- $2,200.00
- Social Security and Medicare
- $765.00
- Illinois tax
- $495.00
Illinois tax for the year
- Withheld from the bonus
- $495.00
- Added by the bonus
- $495.00
- Difference
- $0.00
Illinois withholding by bonus size
What a single filer with $75,000 of other wages has withheld from bonuses of different sizes, and takes home.
| Bonus | Federal | Social Security and Medicare | State | Take-home |
|---|---|---|---|---|
| $1,000 | $220 | $77 | $50 | $654 |
| $5,000 | $1,100 | $383 | $248 | $3,270 |
| $10,000 | $2,200 | $765 | $495 | $6,540 |
| $25,000 | $5,500 | $1,913 | $1,238 | $16,350 |
| $50,000 | $11,000 | $3,825 | $2,475 | $32,700 |
Illinois tax withheld vs. owed
The Illinois tax withheld from a $10,000 bonus against the tax the bonus adds to a single filer's year. Over-withholding comes back in your refund; under-withholding is due when you file.
| Annual wages | Withheld | Tax added | Difference |
|---|---|---|---|
| $40,000 | $495 | $495 | $0 |
| $75,000 | $495 | $495 | $0 |
| $150,000 | $495 | $495 | $0 |
| $300,000 | $495 | $495 | $0 |
Illinois bonus tax questions
What is the Illinois bonus tax rate for 2026?
Illinois has no separate bonus tax rate: a bonus is withheld at the state's flat 4.95% income tax rate, like any other wages. On a $10,000 bonus that is $495 of Illinois tax.
Is a bonus taxed more than regular pay in Illinois?
No. When you file, a bonus is taxed at the same Illinois rates as the rest of your wages; only the withholding differs. For a single filer with $75,000 of wages, a $10,000 bonus adds $495 to the year's Illinois tax and has $495 withheld, so withholding matches the tax.
Does Illinois have a supplemental wage tax rate?
No. Illinois's withholding booklet has no supplemental wage section: it subtracts exemption allowances from wages and withholds 4.95% of the rest. Publication 130 lists bonuses, overtime and commissions as wages like any other, so a $10,000 bonus has $495 withheld before any allowance.
What the calculator leaves out
- Illinois has no separate bonus rule; the calculator applies 4.95% to the whole bonus with no exemption allowance.
- Illinois withholds every kind of wage at its flat 4.95% income tax rate, so bonus withholding matches the tax on the bonus.
Federal income tax is withheld at the 22% supplemental rate, 37% on supplemental pay above $1,000,000 in a year. Social Security and Medicare treat the bonus as the year's last pay, so wages above $184,500 owe no more Social Security. Filing status changes only the annual comparison.