Hi precisebooks1,
The 1A and 1B amounts on your BAS are for the GST you collected on sales and paid on purchases. If there's no amendment showing, I'd recommend running the GST/BAS Detail and GST/BAS Summary report and compare to Transactions by Tax Code and double-checking the transactions.
- Click on the GST tab, and locate the specific BAS period.
- Click on the drop-down arrow and click on View BAS Summary or BAS Detail.
- You can also click on the Run reports button and select Transactions by Tax Code.
- Look for any transactions that can be coded with the wrong tax code.
You can also check this link to learn more about What to do when BAS amounts look incorrect and Simpler GST FAQ.
Post again in the Community if you have more questions. I'll be around to help you!