Legislation has been passed for Single Touch Payroll for businesses with 19 or less employees to commence reporting from 1/7/2019. Businesses with 20 or more employees are already required to report using Single Touch Payroll from 1/7/2018. Micro businesses with less than 4 employees appear to be able to report quarterly instead of at the end of each pay run through their registered tax agent. The ATO is compiling a list of low cost Single Touch Payroll software for $10 per month or less, keep an eye out for this list if you don't have Single Touch Payroll compliant software yet.
As always, seek independent professional advice before acting on this general in nature information.