If your company is operating in batch mode
From the Tasks menu, select System, then Unpost.
If this option is not available, then your company is more than likely set to Real-Time mode, or you do not have access to this area because of settings in the User Security window.
To begin unposting, select OK.
When finished, all transactions within the journals you chose (including transactions that are dated in the current accounting period and future accounting periods) are temporarily removed to the general ledger.
Note: Before you can change accounting periods, you must post all journals.
Sage 50 allows you to edit a single transaction in a past or future accounting period without having to unpost the journal.
Enter your changes and select Save.
The transaction is automatically posted to the general ledger.