How can I reconnect my AMEX account to Quickbooks? It worked before, but now gives an OAuth error

American Express now utilizes OAuth to authenticate card members for access via their browser or the American Express mobile app. During this process, users can select a card to enroll in their account, Casper.

I recommend contacting the American Express support team for detailed instructions on how the OAuth authentication process works.

Once you've completed that step, we can return to your QuickBooks Online account to reconnect your AmEx account to Online Banking. Be sure to prepare your AmEx mobile app to authenticate QuickBooks Online's connection attempt.

If the connection between AmEx and QuickBooks Online is unsuccessful, we recommend contacting our Live Support Team. They can provide further instructions on how to proceed or guide you in downloading your bank transactions directly from the AmEx website.

Temporarily, you can manually download a CSV file of your bank transactions from AmEx and import it into QuickBooks Online. You can follow the steps outlined in this article to complete the process: Manually upload transactions into QuickBooks Online.

If you need any assistance with this or have further questions, we're here to help.