How to undo a credit card reconciliation?

The feature to undo a reconciliation is exclusive to the QuickBooks Online Accountant version, marcia-mao-gaoya.

Before anything else, I'd like to ask what specific error you encountered when modifying an account in a reconciled credit card account? Additional details are much appreciated so we can address your concerns by providing an accurate resolution.

If the We can help you fix it error is prompted, it means that the changes made affect your beginning balance. 

Since you've already tried manually undoing the transactions from the Chart of Accounts, I recommend seeking professional advice from your accountant. They know the best process to ensure your books remain accurate. If you don't have one, you can utilize our accountant tool to look for one in your area.

As further help in correcting your beginning balance for the current month, let me add this article: Fix issues for accounts you've reconciled in the past in QuickBooks Online.

This article can help generate a report each time you finish reconciling: How do I view, print, or export a reconciliation report?

We have QuickBooks Live Expert Assisted that are always available to help you with best practices in setting up and making the most out of QuickBooks Online.

I'm more than willing to help if you have any other concerns with fixing reconciliation issues in QuickBooks Online. I'll ensure your needs are taken care of.