Welcome to the Community, @ra20.
This issue has been recently reported and already closed. The update we've got from our engineers is to try connecting your NatWest bank account via an incognito or a different browser.
Before we proceed, please make sure that you logged out from your bank's website or app for more than 15 minutes. This way, we can avoid getting the same error upon connecting the NatWest bank account.
To use a private browser, here's how:
- Google Chrome: Ctrl + Shift + N
- Internet Explorer: Ctrl + Shift + P
- Mozilla Firefox: Ctrl + Shift + P
- Safari: Command + Option + P
Once logged in, go back and try to connect your NatWest bank account again to double-check. For your reference, you can read this article for further guidance: Connect your Bank Accounts to QuickBooks Self-Employed.
If this works, it means that you need to clear your browser's cache so the system can start fresh.
If you get the same result while using a private browser, I recommend switching to a different browser.
In case you have duplicate transactions in the future, you can check out this article to learn how to handle them: Handle Duplicate Transactions in QuickBooks Self-Employed.
Fill me in if you have further questions. I’ll be around if you need any help.
