A method of obtaining user subscription data pertaining to a subscriber in a telecommunication network, said method comprising the steps of receiving, by a coexistence function, a trigger from a Network Function, NF, said trigger indicating a need for user subscription data pertaining to said subscriber, determining, by said coexistence function, that said user subscription data is not available in a Unified Data Repository of said telecommunication network, obtaining, by said coexistence function, said user subscription data from a user data repository, upon said determining that said user subscription data is not available with said unified data repository, wherein said user data repository and said unified data repository are accessible by two separate communication interfaces, and transmitting, by said coexistence function, to said NF, said obtained user subscription data. A corresponding coexistence function and computer program product are also presented herein.