Connecting QuickBooks with NatWest account, keep getting an error message and to try again in a few hours

Thanks for posting in the Community forum, jumpingjakesccs.

Let me get the help you need to ensure that you'd able to connect Natwest bank account into your QuickBooks Online.

To start, I recommend accessing your account in a Private browsing window first to verify if this is caused by the system or your browser. Here are the keyboard shortcuts that will help you accomplish this in all supported browsers:

• Google Chrome: press Ctrl + Shift + N
• Mozilla Firefox: press Ctrl + Shift + P
• Internet Explorer: press Ctrl + Shift + P
• Safari: press Command + Shift +N

Once able to open a private browser, try to connect bank account again by following these steps:

1. Go to Banking tab in the left navigation panel.
2. Click either Connect account or Add account button.
3. Enter your login details that you use for online banking, then click Continue.
4. Click Agree.
5. Choose Connect.

For detailed steps, here's a great resource that you can check: Connect bank and credit card accounts to QuickBooks Online.

I'd appreciate if you can update me on how it goes. I'm always here to help in connecting your bank account.  Have a great day!