Hi christine42,
Thank you for reaching out. Was there something specific you were wanting to test? I may be able to give you information on how to do this.
You can also create a test pay run and choose not to publish pay slips or lodge STP.
If you finalise the test pay run you can still delete it after going to Pay Run Actions > Unlock and then Delete.
Please don't hesitate to reach out for assistance at any time.
Thanks,
Rebecca