Supplemental Earnings
Learn how to manage supplemental earnings and add custom codes in OnTheClock.
Overview
This guide explains how OnTheClock treats supplemental earnings and shows you how to add new supplemental earning codes in OnTheClock.
What are supplemental earnings?
Supplemental earnings refer to income an Employee receives in addition to regular wages. Common types include:
- Bonuses
- Commissions
- Severance pay
- Back pay
- Tips
- Stock options
- Sick pay and vacation pay
Tax treatment of supplemental earnings
The Internal Revenue Service (IRS) allows two methods for withholding federal income tax on supplemental wages.
Aggregate method
Add the supplemental amount to the Employee’s regular wages and withhold based on the Employee’s Form W-4 elections.
Example (2025):
Jake earns $25 per hour and is paid weekly. One week, Jake works 32 hours and uses 8 hours of sick time. OnTheClock adds the sick-time earnings to Jake’s regular wages and withholds taxes on the combined amount using his Form W-4.
Percentage method
Apply the flat supplemental rate—22 percent for 2025—to the supplemental amount.
Example (2025):
Mindy earns a bi-weekly salary of $2,500 and also receives commissions and quarterly bonuses paid on off-cycle payrolls. Her Employer withholds federal income tax on those commissions and bonuses at the 22 percent supplemental rate.