A potential recipient may provide one of the routing permission codes to the sender who may send communications or otherwise on whose behalf communications may be sent. Alternatively, a routing permission code may be provided to the potential recipient by the entity and the potential recipient enters the routing permission code in the user configuration list 422. In an example, a system associated with the sender may cause to be transmitted or may transmit a routing permission code to the software platform 402, which the blocking software 410 may add to the user configuration list 422. In an example, the blocking software 410 may associate the received routing permission code with the sender of the routing permission code.
As an example of using routing permission codes, a user may be using an on-line service (such as to sign up for the service) where the registration process may require that the user enter a verification code that the on-line service may transmit to the telephone number of the user. The user may be prompted for a routing permission code to be included in the communication that includes the verification code. The user may enter one of the routing permission codes from the user configuration list 422.