The invention relates to a method for securing the execution of an onboard NFC application in a secure element which does not include a native OTA application. The secure element interacts with a mobile terminal including a removable card. According to the invention, the method includes recording an identifier of the removable card in the secure element no later than when the NFC application is loaded onto the secure element. When an event occurs, a verification is made, in the secure element, whether or not the identifier of the removable card present in the mobile terminal corresponds to the identifier previously stored in the secure element, in order to detect a possible change of the removable card.