The present invention relates to a method and a network element in a telecommunications system. The telecommunications system comprises at least two telecommunications networks and means for providing number portability service between the networks and also supplementary telecommunications services. The method comprises the steps of initiating a set-up procedure for communications between two stations, sending an enquiry to the number portability service, determining if the called station is a ported station, and informing the supplementary telecommunications service of the results of said determination before initiating an use of said supplementary telecommunications service.