When an employee takes the full period as unpaid leave, enter €0 in the payroll. In such cases, no PRSI, USC or PAYE is calculated. If the employee is on a cumulative tax basis, any refund they are entitled to will be processed automatically when they start receiving pay again.

If the employee takes a number of days unpaid leave within that period, you will have to manually work out the amount you need to deduct from the normal pay if they are salary based.  

The Alternative is to adjust the amount of hours if hourly paid and process the payslip accordingly.

To keep seasonal or zero hour contract employees on BrightPay, finalise the employee's payslips with zero pay until they are ready to be paid again. At this point, you can add the salary / hours to the payslip and continue to process as usual.