All One Billing (AIO) is a core Convergent Billing System platform that provides mediation of usage for any service and network, multi-play subscription management with both event based and batch rating, discounting and invoicing, including support for account hierarchy, resellers commissioning, large fleet, roaming and wholesales billing all in one. Multi-Tenanted by design, it is a core BSS component for modern Telcos to manage retail, corporate and wholesales with one platform, as well as to empower and reduce costs of operation for MVNEs and MVNOs.