It is very important to keep your security up to date contact just in case your SIM’s data is compromised. When this happens, you receive a notification via e-mail and they will be notified via text message.
To do this, open DFNDR, click Tools and enter Anti-theft.
Enter your access code and click Confirm. If you do not remember your code, click here.
Now click Register security contact.
Click the calendar icon to access contacts.
Select the contact you want to register.
Click Register to finish.