Method for transferring data upon request using permanent identifier

The method for transferring data according to the present invention sends data as part of a first type of permanent identifier associated with an end user in a communication system. The first type of permanent identifier is sent along with a second type of permanent identifier, also associated with the end user, during a communication procedure prior to establishing a traffic channel in the communication system. Besides the data, the permanent identifier of the first type includes routing information to a home system forming part of the communication system. The end user also stores the sent permanent identifier of the first type, and in response to receiving the stored permanent identifier of the first type in a communication, will generate a new permanent identifier of the first type. In this manner, a destination entity receiving the permanent identifiers of the first type from the home system, can request more data from the end user by having a received permanent identifier of the first type re-sent to the end user.