The present invention relates to method and arrangements to provide information related to user devices in a telecommunication system (TS). The system comprises at least one network domain (HPLMN, WCDMA) that is associated with a central database (DCR). The method comprises identification in the central database (DCR) of a first request (REQ1, REQI1) to provide to at least one data analysis function, user identity information related to all user devices that notifies attachment to the at least one network domain (HPLMN, WCDMA). Attachment notification from a requested user device (A, B) to the network domain is then detected in the central database.