Can I fix an incorrect end date in a reconciliation once it's done?

Let me make it up to you by ensuring you can fix the end date of your reconciled account in QuickBooks Online. 

Once your account is reconciled, we can only change the end date by unreconciling it. However, please keep in mind that even small changes can unbalance your accounts. That said, I recommend reaching out to your accountant when doing the process to ensure the accuracy of your accounts. 

Once you're ready to undo the reconciliation, here's how: 

1. Go to the Accounting menu, then select Chart of Accounts. 
2. Select the account you're working on, and click on View Register.
3. Find the transaction you want to Unreconcile. 
4. Select the transaction to expand the view.
5. In the checkmark ✔ column, select the box with the "R" until the box is blank. This removes the transaction from the reconciliation.
6. Select Save.
7. Close the account register.
   
   
   

For a more detailed step-by-step procedure for this process, here's an article you can refer to for more details: Undo or remove transactions from reconciliations in QuickBooks Online.

In case you encounter any issues while reconciling, you can check out this article to learn about fixing them: Fix issues at the end of reconciliation in QuickBooks Online. 

You can post anytime if you have more reconciliation or QBO-related concerns. Please know the Community has your back. Take care always.