If you cannot locate discrepancies when reconciling an account, you can undo
your last reconciliation and start again.
If you want to change the date of your opening balance you'll
need to undo your previous reconciliation. Even though you've never reconciled the account, QuickBooks considers setting up the account
with an opening balance and date your first reconciliation. When you redo the reconciliation you'll be able to enter the correct date.
To do this task
Make sure you back up your data before you begin.
Go to the Banking menu and then click Reconcile.
In the Begin Reconciliation window, click Locate Discrepancies.
Click Discrepancy Report or Previous Reports to view the list of discrepancies.
Click Undo Last Reconciliation.
Reconciliation to repeat the reconciliation process from the beginning.