In QuickBooks Online you have to prepare BAS in chronological order, which may be why you cannot see the last financial year in the GST section.
If this is the first time you're preparing a BAS, you are able to set the first BAS to be a period in the last financial year, by selecting Get Started, then choosing the date range.
If you have already lodged a BAS and would like to go back to prepare a BAS before the date of the lodged BAS, you will have to get the BAS unlodged by one of our Customer Success Team members and then begin lodging from the last financial year.
To contact our team:
In your QuickBooks Online, click the Help menu in the upper-right corner.
On the Search tab, click an article and select Contact us at the bottom. Then, enter the details of your concern.
Choose how you would like to connect with them: either via Callback or Chat.