In the final BAS report, the GST collected on sales is negative figure, and ATO BAS 1A item require this figure should be >=0.

The BAS sales figure will depend on the transactions with the correct tax codes, Jason_zf_hwang. A negative amount can be caused by an amendment. Let's go ahead and check it out. 

We'll pull up the GST Amendments report. This will show if any amendments or adjustments are made.

1. Click GST.
2. Click Run reports, then select GST Amendments.

If there's no amendment, let's pull up the GST Summary report. This will show the total sales or purchase tax amount. Let's compare if the A1 tax amount in the report is the same with the BAS return.

1. On the GST page.
2. Click Run reports, then select GST Summary. 

If they're the same, the BAS figures are accurate. Although, if there's a discrepancy, this is a known issue. Some customers are having an incorrect GST collected sales amount when preparing the BAS return. While we're working for a resolution, you'll have to submit the return to the ATO outside QBO.

I also suggest reaching out to our customer care support so you'll get added to the list of affected users. Here's how:

1. Click Help inside QuickBooks Online.
2. Select Contact us.
3. Enter "Incorrect A1 amount in the BAS return" in the description field, then click Let's talk.
4. Select Start a chat or Get a callback. 

If there's something else we can do for you, please shoot a comment below.