There are a few reasons why your Touch ID may have been turned off: 1. You have changed your service provider 2. You have recently changed your User ID or Password 3. You have not logged into your Citi Mobile App by entering your password for the past 45 days 4. You might have changed your SIM card 5. Your online account is locked because you have exceeded the maximum number of password tries 6. You have entered the wrong OTP when signed on for 3 times 7. You have enabled Touch ID sensor for your account on a different devic8. Your Citibank User ID is deleted in our system