You can forward your US telephone number to another US phone. It would cost from your outgoing plan, and if you don’t have an outgoing plan, it is 2ยข per minute for forwarding. If you wish to forward to an international number, then it won’t cost minutes from your allotment, but you would have to pay from your funds pool. The rate will vary based on the destination number you are forwarding to. To keep things simple, you should just use a SIP client, or SIP phone.