The bonus tax rate is the scale used by the IRS to tax the extra money such as bonuses. In the U.S., individual bonuses are charged at a flat rate of 22% federal tax in case it is not attached to regular earnings. This is the rate that is used on bonuses less than 1 million. Higher than 1 million, the amount exceeding it is imposed with 37% tax. Nevertheless, this flat-rate excludes the state taxes, Social Security and Medicare deductions which are also deductible. Your net-pay may differ in the amount you will take home base on your overall annual earning and tax bracket.