Method and system for tracing a subscription

The invention relates to a method and system for tracing a subscription in a telecommunication system. The telecommunication system comprises a local exchange, an access node connected to the local exchange, a wireless link system connected to the access node and a telecommunication terminal connected via the wireless link system to the access node. In the telecommunication system, an IMEI code corresponding to the telecommunication terminal and an IMSI code corresponding to the subscriber have been defined. In the method of the invention, the tracing of the subscription is started on the basis of the IMEI code and the tracing is converted into IMSI tracing. In the system, the access node comprises means for tracing a subscription on the basis of the IMEI code and means for converting the IMEI tracing into IMSI tracing.