Yes, you can, jdj6268-outlook-.

The Undo button is only available in QuickBooks Online Accountant. I'd recommend reaching out to your accountant to let them undo the reconciliation on your behalf. You can share this article for the detailed steps: Undoing a Client's Reconciliation.

Aside from that, you can also manually edit each transaction to undo the reconciliation. Here's how:

1. Go to the Gear icon and then select Chart of accounts.
2. Search the account that has the reconciled transaction. 
3. Select View register.
4. Find the reconciled (R) transactions.
5. Select the transaction to expand the view.
6. In the checkmark ✔ column, click the box until it's blank. This removes the transaction from the reconciliation.
7. Click Save.
8. Close the account register.

For more details, please see this article: Undo or Remove Transactions from Reconciliations.

Additionally, I've added these resources that'll help you handle and manage your account's reconciliation in QuickBooks Online. This way, you can ensure your books are accurate: 

• Tips for Year-End Reconciliation
• How do I View, Print, or Export a Reconciliation Report?

Please let me know how it goes. I want to make sure this is resolved for you. I'll get back to this thread if you need more assistance in reconciling your books.

Got It Thank You

Thanks for following up with the Community, jackjackson1977.

I'm happy to hear CharleneMae_F was able to help with learning more about how previous reconciliations can be undone.

You'll also be able to find many detailed resources about using QuickBooks in our help article archives.

Please feel welcome to send a reply here or create a new thread if there's ever any questions. The Community's always here to help. Have a wonderful day!