Hi Rosalind,
If you're no longer registered for GST and PAYG, you don't need to prepare BAS in QuickBooks Online, as long as your recorded transactions are free from GST tax codes.
Furthermore, since we're unable to turn off the GST in QuickBooks Online, you'll have to set your transactions to Out of scope. Here's also how to set your tax settings to Out of scope.
- Click on the Settings icon in QBO.
- Click on Account & Settings.
- Click on Advanced tab.
- Under Accounting tab, select Default tax rate selection to Out of scope.
- Click on Save and then click on Done.
When you create your transactions it should be set to Out of scope tax code to not calculate tax on them.
Post again in the Community if you have other QBO concern. I'm around to help you.