This article describes on how-to rerate / recalculate already rated calls, e.g. in the rate plan the amount was incorrect, made calls were rated with the wrong rate and not, after correcting the rates, you want to rerate / recalculate already rated calls.

1. Login to BTEL with Admin rights
2. Ensure you entered the correct rates 
3. Goto Admin --> Billing --> Tenants Dashboard
4. At the main window click the "Recalculate" button
5. At the Billing Recalculation screen Select the Tenant -or- All
6. Select the From and To Date
7. Click Recalculate
8. Wait until the Recalculation is done and now you can run new / accurate call billing reports.