US Patent 11533404 On net bus for distributing fax transmissions

Method and system are described for fax transmission distribution by an online fax service provider. In one embodiment, an electronic document is received, over a computer network, to be routed to a fax telephone number. A request is transmitted to an online database to determine whether the fax telephone number is registered to not receive incoming fax transmissions over a circuit-switched network. In response to determining that the fax telephone number is registered, the electronic document is transmitted to a destination address. In response to determining that the fax telephone number is not registered, an outgoing call is placed to the fax telephone number and the electronic document is transmitted in a fax format over the outgoing call.