Hi @rhys6,

Bank error 103 occurs when your banking credentials entered in QuickBooks Online (QBO) do not match the credentials on file with your bank. To resolve this issue, I recommend contacting our Live Support team, as they have the tools and resources necessary to address the matter and provide a solution.

Here's how to reach out to them:

1. Go to the Help (?) icon.
2. Enter "Live support" in the search box, then select Contact Us.
3. Provide a brief description of your concern, then hit Continue.
4. Choose either Appointment, Chat, or Callback options.

Before reaching out, I suggest checking the support hours to ensure you can connect with a representative at a convenient time.

In the meantime, you can manually upload your bank transactions into QBO. To make sure the upload is successful, refer to this article for the correct formatting: Format CSV files in Excel to get bank transactions into QuickBooks.

If you have any additional concerns, please let us know in the comments below.