Single Touch Payroll (STP) is a reporting change for employers, by the ATO.
It starts from 1 July 2018 for employers with 20 or more employees. Single Touch Payroll will be expanded to include employers with 19 or less employees from 1 July 2019, but employers can opt in (register thru Xero/MYOB) before this date once fully implemented.
You will report payments such as salaries and wages, pay as you go (PAYG) withholding and super information to the ATO at the same time as you process your Payroll, thru existing software.
If you process your own payroll you will need to know this information to be compliant with the ATO.
Once advice from the ATO is received by A Girl Friday that the STP has been implemented in your software for employers with under 19 employees, you may choose to start STP before the 1 July 2019 deadline.