How do you undo a bank reconciliation?

I have all the steps to undo your reconciliation, @catherine-conner.

You can only un-reconcile one transaction at a time. If you need to start over, I'd suggest reaching out to your accountant. They can undo the entire period at once using QuickBooks Online Accountant.

Here's how to invite your accountant:

1. Click the Gear icon in the upper-right corner, and select Manage Users.
2. Go to the Accounting firms tab, and click the Invite button.
3. Enter the accountant's information.
4. Click Save.
5. Let your accountant undo the entire reconciliation.

If you prefer to do it by yourself, follow these instructions to undo reconciled transactions one at a time:

1. Go to the Accounting menu. Then select Chart of Accounts.
2. Find the account and select View register. 
3. To help you focus on this task, filter the register to only include the last 60 days of transactions.
4. Review the check column. If the transaction is reconciled, you’ll see an “R.”
5. Select the box and keep clicking it until it's blank. It removes the transaction from the reconciliation.
   

    

6. Select Save. Then close your register.

I've added here an article that will help you in case you encounter reconciliation issues: Fix issues when you're reconciling accounts.
 

If you want hands-on help, you can get a QuickBooks-certified bookkeeper to show you how to do reconciliations and other tasks: Check out QuickBooks Live.

Please come back if you need any further assistance with this process.