Thanks for visiting the QuickBooks Community, @Ben_Roach.
The due date for paying your BAS for the 2nd quarter may depend on your reporting frequency. You can check with the agency to verify your reporting and payment cycle.
I'll include this link for details: https://www.ato.gov.au/Business/Business-activity-statements-(BAS)/Due-dates-for-lodging-and-paying-....
When lodging a Business Activity Statement (BAS) in QuickBooks Online, you'll need to make sure that the lodging frequency will be the same as your taxes lodging frequency.
To give you in-depth details about this process, please check out these resources:
Please keep in touch with me here for all of your QuickBooks needs. Wishing you and your business continued success in all future endeavors.
