Calculate PAYG on Bonuses and commissions

When Bonus or Commission is used, user is asked to enter the appropriate amount of PAYG to withhold. The calculation for the 3 types of PAYG scenarios are outlined on the ATO website - see https://www.ato.gov.au/tax-rates-and-codes/payg-withholding-schedule-5-tax-table-for-back-payments-commissions-bonuses-and-like-payments/working-out-the-withholding-amount?anchor=Workingoutthewithholdingamount#Workingoutthewithholdingamount. This calculation has been handled by older Reckon products. The calculations are not simple for the individual to do manually and is a task normally expected of a programme that generally calculates PAYG on a payrun.