A debt collector can report their collection once they have obtained collection authority.
That does not depend upon whether the collection authority resulted from an assignment from the current owner, or whether it resulted from purchase of the debt.
If they do not own the debt (i.e., they only have assigned collection authority), the balance reported only reflects the debt balance that they are authorized to collect upon.
If, however, they have acquired the debt, then the reported balance reflects both the amount they are authorized to collect upon, and the amount of debt owed to them. In such cases, if the OC is also reporting, then the OC should update the balance on their account to $0, since there is no longer any debt owed to them.
