A computerized system and method for selecting the nature and/or form of an alert used to announce a call made by a user participating in a customized alter service. The method includes establishing a customized alert service configuration for a participating user, which configuration is then stored on one or more network accessible devices. The participating user uses a first communications terminal to make a call to a second communications terminal, via a first communications service, the second communication terminal then announces the call by activating an alert using a chosen alert descriptor which has been chosen according to the customized alert service configuration for the participating user.