for GST report, why the F5 Summary and the detailed transaction report do not agree under Box 3?

Your accounting basis impacts how GST reports are displayed in QuickBooks Online (QBO). The GST F5 Summary Report is based on the Accrual accounting method by default, and it includes all invoices dated within the reporting period, regardless of their payment status.

As a result, the total difference amount in Box 3 does not reference any specific transaction because the system is using calculated figures based on, and not limited to:

• Rules and mappings of GST codes.
• A GST box calculation.
• A netted total like invoices minus credit notes.
• Rounding or adjustments made at the return level.

To verify your GST information and ensure accuracy before filing, you can generate a GST Liability Report to determine how much you owe.

Please let me know if you have further questions.