Provided is a method for attaching a terminal cooperating with a secure element to the network of a MNO of a visited country. The method includes steps of switching a set of files of said secure element to a new value, including a new SUPI, called entity support SUPI; Building at the level of said secure element an entity support SUCI; Routing an attachment request to said support entity with said entity support SUCI; Decrypting in said support entity said entity support SUCI back in said entity support SUPI; and Swapping said support entity SUPI to the SUPI corresponding to the MNO of the home country. If an authentication is performed that is positive, an attachment acknowledgement message is sent to connect said terminal to said network of said MNO of said visited country.