It's great that you've decided to reach out to us here in the QuickBooks Community! Matching your transactions to the Bank Feed is a great way to stay organized, and ensure your books are up-to-date.
When deciding which tax code to select, I'd recommend consulting with your accountant to come to the best resolution. They're the best equipped to help you make the appropriate selection for how to tax your business transactions. Perhaps some of our accountant contributors in the Community will also chime in with some advice.
If you're not already connected to an accountant, you can find one in your area here: Find an Accountant.