A Provider is a special kind of Customer account. You can use a Provider account to identify calls made from a Provider (Carrier) account.
This allows you to not only associate calls made by a customer but also identify the Provider (Carrier) where the call came from.
A Provider account is usually needed in cases where you have a requirement to reconcile how much you owe your Provider at the end of the month or billing cycle.
CDR2Cloud uses Auth-Codes to identify a calls from your CDR file to a customer and only a single customer can be a identified to a call (cdr record).