Flat Tax Rate
- Optional Supplemental Flat tax rate is 22% for Federal & 6.6% for the State of California.
- Bonus flat tax rate is 22% for Federal & 10.23% for the State of California.
Payroll processors, please keep in mind when processing supplemental or bonus payments that the above rates are only applicable to supplemental payments paid by themselves (not included with any regular pay types), regardless of pay cycle. If the supplemental payments are included with regular pay types, again, regardless of the pay cycle, the Federal and State taxes are calculated on the total combined amount using the regular tax tables. If the supplemental payment amount is large, it would be wise to notify the employee of the tax amounts prior to processing the payment in order to avoid confusion after the payment is issued.