Thank you for making sure you've entered the correct login credentials when connecting to your bank, @RG83. No worries, I’ll be here to help you get rid of the error code 103.

May I know what bank institution you’re using? This will help me verify if there’s a reported issue about this matter. I’d appreciate it if you can add a clarification of it in the comment section below.

Error 103 will appear when login credentials provided into QuickBooks Online don't match those held by your banking institution. There are a few things that could cause this issue:

• When attempting to establish a connection with your banking institution for the first time, you entered the incorrect credentials.
• You choose the incorrect banking institution choice (there are often many to select from).
• You’ll need to change the data in QuickBooks Online if you are currently connected and have updated your credentials with your financial institution. 

To get to the bottom of it, you’ll want to reach out to your bank to verify if they’re performing any system maintenance update. Let’s log in to your bank’s website to check for any notifications that needs your attention. 

If everything looks good on your bank’s website, try to reconnect and ensure to manually enter your credentials.  If the error persists, follow these steps:

1. On the left pane, select the Banking menu and click Add account.
   Note: If you already have an existing bank account in your Chart of Accounts, go to the Action column and select View register (or Account history) drop-down and choose Connect bank.
2. In the search field, enter the bank’s name or enter their URL.
3. If multiple results are displayed, select the bank name in the list for your account.
4. Log in with your user id and password.
5. If you receive the error 103 again, tap the Go back button and proceed to the next name on the list. Repeat this process until you have successfully connected your account.

If you can’t still find or connect to your bank, refer to this article: Unable to find the correct bank in QuickBooks Online.

If the same thing happens, you can refer to this article for more troubleshooting steps: Error 103 or Error 310.

As a workaround, you’ll want to consider manually importing the bank transactions into QuickBooks. Please keep in mind that it will most likely cause duplicates once the issue gets resolved. Thus, you’ll need to exclude them moving forward.

Once everything is settled, you can visit these resources to manage your transactions in QuickBooks:

• Categorize and match bank transactions
• Reconcile an account

Please let me know how it goes or if you have any follow-up questions about setting up bank connection. I'll be here if you need further assistance. Take care always.