Tax on Tax for Solidarity Levy is applicable when Solidarity Levy is paid by the employer for the employee
To activate the Tax on Tax flag, Sicorax HRMS Payroll requires you to insert a new EDF record. Though the new EDF record does not mean that the employee has submitted a new EDF but it's purpose is only to add a new information to the existing EDF record
(Please note that we have been provided with the Tax on Tax Benefit formula/factor by the MRA as per below)
You will also find below an illustration of the PAYE Calculation Slip showing the Tax on Tax/Tax Benefit calculation