I reconnected my bank accounts and now have a years worth of duplicates in my transactions. Is there a way to undo that without going through each individual transaction?

Glad to see you here in the Community, Katie. 

I'd be glad to walk you through how to undo your reconciliation. So let's get started. 

To undo a reconciliation:

1. In QuickBooks Online Accountant, select the client from the drop-down list on the Toolbelt to open the client's company file.

Select the Gear icon on the Toolbar.

Under Tools, select Reconcile.

1. On the Reconcile an account page, select History by account.
2. On the History by account page, select the Account and Report period to locate the reconciliation to undo.
3. From the Action column drop-down list, select Undo.
4. When prompted to confirm, select Yes.
5. In the final confirmation window, select Undo.
6. Select Ok. 

Please refer to the articles below to see the detailed steps on how you can reconcile accounts so they always match your bank and credit card statements. Then, steps on how you can fix beginning balance issues so you can start reconciling.

• Reconcile an account in QuickBooks Online.
• Fix issues for accounts you've reconciled in the past in QuickBooks Online.

I look forward to serving you to the best of my ability. If you need more help with your bank transactions, please know the Community has your back.