Supplemental wages are any wages you pay employees beyond typical salaried or hourly pay. Bonuses, including holiday bonuses, are one of the most common types of supplemental wages, but the IRS classifies several other payments as supplemental wages too. For instance, sales commissions, sick leave, severance pay, financial awards or prizes, overtime, and tips all count as supplemental wages. If you pay your employee their supplemental wages as a separate payment from their typical wages, you'll calculate the tax withholding amounts on the supplemental pay differently—and that's what the calculator on this page is for.