Abstract: The present invention relates to a method and device for activating a subscription in a cellular network comprising a register unit for a cellular network, said register unit storing at least one unique identity number which identifies a subscriber identity module. The stored identity number is registered in a cellular network subscription. The method is further characterized in the steps of: the register unit receiving the unique identity number for a subscriber identity module when the module is activated, and the register further assigning an authentication number with the received identity number—so that it defines the registered subscription.