Hi there,
Thanks for reaching out to us here in the Community. I'd be happy to shed some light on how to add/match your bank transaction in QuickBooks Online.
Based on your question, it sounds like you've made a sales tax payment outside of QuickBooks Online, and that transaction is now appearing in your Bank Feed. Although you've filed the sales tax in QuickBooks, you'll also have to record the payment in order to match your bank transaction in your account.
To see the steps on how to record a sales tax payment, take a look at this helpful Community article: File Sales Tax. This article will guide you through preparing your return, closing your sales tax period in QuickBooks Online, and recording a payment to or refund from the CRA.
Once you've marked your sales tax filing as paid, you'll be able to use the Find Match feature in the Bank Feed to post your transaction. The tax code you should be selecting for this type of transaction is Out Of Scope, as there's no charged sales tax. The category you choose is up to you. You can also consult with your accountant to get their advice on how to categorize this transaction.
If you have any other questions, or if I've missed the mark in my response, please don't hesitate to reach back out in the comments below.
Cheers!