I pressed GST instead of out of scope when reviewing banking, how do I go in and change

Hi amboyle57,

You can undo the transaction added from the Banking tab so you can change the correct GST code on it. 

Here's how.

1. On Transactions tab select Banking.
2. On Categorised tab, select Undo on the transaction that needs to be edited.
3. Go to For Review tab and edit the transaction.
4. Click Add if details are correct. 

Feel free to read this article for your future reference: Categorise and match online bank transactions in QuickBooks Online.

Please reach out again if you have any other questions. Have a great day.