We have updated our tax calculation logic so that if an employee receives multiple payslips in a single pay period, their earnings from all payslips will be included when determining the tax calculations on other payslips from that pay period.
In other words, tax calculations now consider
all
payments within the current pay cycle when determining tax payments. This will also impact Schedule 5 payments (back pay, lump sum, etc.). Accordingly, when an employer splits a schedule 5 payment off into it's own payslip, the tax calculation is no longer manual, and will use earnings from the other payslip(s) in that pay period to correctly calculate the tax owed.