A PIN is a secure 4 digit code containing a combination of any numbers between 0000-9999. Clearwire Corp uses the PIN as an additional security measure to validate all users and to prevent someone else from entering their account. Therefore, Clearwire requires that all users personally set up their PIN during the service activation flows. Due to the sensitive security nature of the PIN, users SHOULD NOT use the last 4 digits of their Social Security number or their Phone number. If the PIN number is ever forgotten, users can always reset the PIN number by visiting that their “My Account” and scrolling down to the “Security Info” section located within the “Profile” tab. Alternatively, users can also contact Customer Service to reset their PIN.