Abstract: The problems with reaching unavailable mobile telephones, and the unnecessary costs associated therewith are avoided by a) marking as unavailable a wireless telephone to which a wireless telephone call could not successfully be completed; b) waiting for the wireless telephone to register, i.e., signal its availability to receive calls; and c) notifying the caller of the wireless telephone call that could not successfully complete that the wireless telephone is now available. Optionally, any call attempts to the wireless telephone during this waiting period are disallowed, i.e., no attempt is made to contact the wireless telephone over the wireless telephone service provider's network.