Hello there, paulettem.

Let me walk you through how to undo bank reconciliation in QuickBooks Online (QBO). You can only undo reconciled transactions individually to avoid account imbalances.

Here's how:

1. Go to the Gear icon, then Chart of accounts.
2. Click the View register of your bank.
3. To help you focus on this task, filter the register to only include the last 60 days of transactions.
4. If the transaction is reconciled, you’ll see an “R” in the checkmark ✔ column.
5. Select the transaction to expand the view.
6. In the checkmark ✔ column, select the box with the “R” until the box is blank. This removes the transaction from the reconciliation.
7. Select Save.

However, if you prefer undoing an entire bank reconciliation, it's best to reach out to an accountant if you have one. However, if you don't have one yet you can refer to this ProAdvisor link for advice on how to properly handle this matter, so your report will reflect accurate data.

Furthermore, I've added this article in case you encounter any issues during the reconciliation process: Fix issues at the end of a reconciliation in QuickBooks Online.

Feel free to come back to this thread if you need further assistance undoing reconciliation in QBO. Take care.