Hi HarleyRiderGA,

Thanks for your post in the Community!

You can only unreconcile 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.

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.

If your accountant has a QuickBooks Online for accountants you can invite them using the steps below:

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.

Check this link also to learn more about how to: Undo or remove transactions from reconciliations in QuickBooks Online.

If there's anything else that I can help you with, please let me know in the comments. Stay safe!