What is Supplemental Wages?
Bonuses, commissions, and other extras - taxed under special withholding rules, not the same as regular pay.
Supplemental Wages: definition
Supplemental wages are compensation beyond ordinary salary or hourly pay. For federal income tax withholding, employers can use the flat-rate method (a set supplemental rate applied directly, when supplemental wages are paid separately) or the aggregate method (combining the supplemental payment with regular wages and withholding as if it were one paycheck). This affects how much tax is withheld from a bonus, though it does not change the actual tax owed for the year.
- Includes bonuses, commissions, overtime, severance, and awards
- Flat-rate method: a set supplemental withholding percentage
- Aggregate method: combined with regular wages for withholding
- Withholding method affects timing, not the final annual tax owed
How Fintra handles it
Fintra payroll identifies supplemental wages and applies the appropriate withholding method - flat or aggregate - so bonuses and commissions are taxed correctly for withholding, then posts the wages and liabilities to the ledger. Because everything runs on one model, supplemental payments flow into year-end W-2 wages accurately alongside regular pay.
- Supplemental wages identified and withheld by the correct method
- Bonuses and commissions posted with regular pay to the ledger
- Included accurately in year-end W-2 taxable wages
Worked example
Frequently asked questions
What are examples of supplemental wages?
Bonuses, commissions, overtime pay, severance, accumulated sick leave payouts, awards, prizes, and certain other payments beyond regular salary or hourly wages. They are compensation, but the IRS allows special withholding methods for them.
How are supplemental wages taxed?
For federal income tax withholding, employers use either the flat-rate method (a set supplemental percentage, when paid separately) or the aggregate method (combined with regular wages). This affects withholding at the time of payment. The actual tax owed is settled on the annual return.
Why does my bonus seem taxed at a higher rate?
The flat supplemental withholding rate can be higher than your usual paycheck withholding, so a bonus can look heavily taxed. But this is withholding, not the final tax - if too much is withheld, it is refunded when you file. The bonus is not taxed at a permanently higher rate.
What is the difference between the flat and aggregate methods?
The flat method applies a fixed supplemental percentage directly to the payment, used when supplemental wages are paid separately. The aggregate method adds the supplemental payment to regular wages and withholds as if it were one combined paycheck. Employers choose based on how the payment is made.
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