How do I change the Period End Date after completing a reconciliation? The one entered is not correct.

I appreciate you for joining the Community, @lonniebosenko.

Let's work hand-in-hand to undo the reconciliation process in QuickBooks Online (QBO), so we can change the end period date after reconciling. 

The undo option after completing a reconciliation is only available in QuickBooks Online Accountant (QBOA). To change the period end date of reconciliation, I'd suggest inviting your accountant to your company and allowing them to undo the reconciliation at once. 

Once done, here's how:

1. On your accountant's QBOA account, go to the Accounting menu and select the Reconcile tab.
2. Click History by account.
3. Select the account you want to undo reconciliation and date range from the dropdowns.
4. Search for the reconciliation on the list.
5. Click View report to open the reconciliation report and review any discrepancies you want to make.
6. Once ready, click the dropdown button in the Action column and select Undo.
7. Click Yes, then Undo to confirm.

When finished, you can start redoing the reconciliation and change the end date from there.

However, if you have no accountant and you prefer to undo the reconciliation by yourself, you can follow these steps: 

1. Go to the Accounting menu and select Chart of Accounts.
2. Find the account you want to undo and click View register.
3. Review the check column. You'll see an R if the transaction is reconciled.
4. To undo it, select the box and keep clicking until it's blank. Doing so removes the transaction from reconciliation.
5. Select Save and close the register.

If you're done, you may reconcile again and change the end date to correct the changes.

If ever you encounter unmatched statements at the end of a reconciliation, please see this article: Fix issues at the end of a reconciliation in QuickBooks Online. This will allow you to review the opening and beginning balances of your account to know if they're accurate.

If you have additional questions about reconciling, please let me know by clicking the Reply button below. I'd always be glad to offer help. Have a nice day!