Is state income tax withholding on supplemental wages handled differently than withholding on regular wages?

Author: Rena Pirsos, XpertHR Legal Editor

The answer depends on state law. Many states allow flat rate withholding from supplemental wages at rates that vary widely. Other states require supplemental wages to be aggregated. A handful of states do not provide a supplemental tax rate at all. Employers should check the law of the states in which they pay wages.