I have linked two bank accounts from the same bank but need to add another account from a different account. It’s not letting me saying it’s already linked to an account

We can perform some troubleshooting steps to isolate this issue, @userlouisa_walsh.

Before we start, I’d recommend reaching out with your bank and check if they are having a maintenance schedule or ongoing issues on their end. Thus, it could be the reason you’re unable to link your account to QuickBooks Online (QBO). 

Nevertheless, let’s access your account on a private window (incognito) and link your account from there. This way, we can check if this issue is caused by stored cache from the browser. QBO uses browser cache to run swiftly. This helps load the page faster on your next visit.

When gets outdated, it can cause issues and affects your browsing performance. Using a private window doesn’t save any cache files, thus, it’s best in verifying the issue. To start, here are the keyboard shortcuts in opening a private window:

•  Press keys: Ctrl + Shift + N (Google Chrome browser)
•  Press keys: Ctrl + Shift + P (Mozilla Firefox browser)
•  Press keys: Command + Shift + N (For Safari browser)

Once logged in, link your account again to double-check. If you’re able to do so, go back to your regular browser and clear its cache. If the issue persists, try using other supported browsers. This way, we can see and check if this is a browser-integrated issue.

When everything is in place, you can start categorising and reconciling your accounts.

If there’s anything else I can help in supervising your accounts, you can always tag me in your reply. I’d be more than happy to assist you. Take care and stay well.