The ATO have provided a checklist for Employers to get ready for Single Touch Payroll. The checklist can be found here: https://www.ato.gov.au/Business/Single-Touch-Payroll/Get-ready-for-Single-Touch-Payroll
Step 3 of the "Start reporting checklist" is "Ask your software provider how your software will connect to the ATO".
Cashbook will connect to the ATO through a Sending Service Provider (SSP).
Practical Systems has picked SuperChoice to be the SSP, and as such you do not need to contact the ATO to set up a connection. You will need to register your business details with SuperChoice before you can submit Single Touch Payroll reports. Click here to register now.
This means you do not need an AUSKey to submit Single Touch Payroll information via Cashbook.
Note: If you have already registered your business details with SuperChoice for SuperStream Contributions, please contact us for assistance.