A temporary ENUM architecture assigns a temporary ENUM at call time. For an originated communication requiring routing to a party which needs a particular callback format not supported, the TempENUM provides consistency with the specific format required by the receiving party. The TempENUM is assigned for the duration of the call or communication, or for a given amount of time thereafter. The TempENUM service gateway includes a TempENUM database, a module that assigns a suitable TempENUM at the time of call routing, and a module that handles a lookup in the TempENUM database, and maps the assigned TempENUM to a calling party identifier (CgPID). The TempENUM database stores a TempENUM from a coordinator system and relates the actual calling party identifier (CgPID) for use in callback attempts. Either during the initial call or communication, or shortly thereafter, the receiving party uses the TempENUM number to return communication the initial caller.