Once Single Touch Payroll (STP) has been reported to the ATO, there's no way to undo or delete the Event.
Negative reversals or missing banking files are common reasons why certain STP events might not appear in the ATO/BAS portal. Negative reversals do not generate an EFT (Electronic Funds Transfer) file, and missing banking files result in pay events not being reflected in the portal.
To correct values in myGov; a supplementary pay slip is required. Once a supplementary payslip has been reported to the ATO via STP2, the employees' YTD values will be updated.
Creating a Supplementary payslip to correct reported STP figures.
To correct values in the Business Portal, modify the values manually in the Business Portal.