It is disclosed a method and trusted execution environments (TEE) of assigning a selected identifier to an application. A request is received to load or install, within or outside a profile domain, of an application with a selected identifier. It is checked that the selected identifier is not already stored in an application registry entry outside the profile registry 230, 302. If it is requested to load or install the application in the selected profile domain, the selected identifier is assigned to said application if the selected identifier is not already stored in an application entry of a profile domain registry associated with the selected profile domain. If it is requested to load or install the application outside any profile domain, the selected identifier is assigned to said application if the selected identifier is not already stored in an application entry of any of at least two profile domain registries.