Thank you for reaching out and for your effort in trying to reconnect your Amex account to QuickBooks, @beeswaxandbutter.
305 usually occurs when the connection to your bank or credit card account expires or gets updated by your bank. Some banks require you to reconnect every 90 days, while others only need updates every 18 months.
To assist you further with resolving this connection issue, you can contact our live support team once more to get the latest updates and further assistance.
Please follow these steps:
- Log in to your QuickBooks account on your computer or through the web browser.
- Navigate to the (?) Help menu.
- Enter "live support" in the Search questions, keywords, or topics field.
- Click on Contact Us.
- Choose either the Chat or Callback option.
You can find details about their support hours on this page, so you can get in touch at a time that’s convenient for you: Get help with QuickBooks products and services.
Additionally, I'll leave this article for your future use when you want to reconcile your transactions into QBO: Reconcile an account in QuickBooks Online.
You can always return to this thread if you have more questions.
