The main reason why the telecommunications card replacement terminal receives a text message is that the new mobile phone card is easy to occur if the device is replaced or the area where the replacement is used. This is not to say fraud, but to say that the new card abnormal telecommunications will stop and sign anti-fraud.
This situation is generally the telecom card, because the telecom card only fills in the simple information at the time of application and does not upload a photo, and is authenticated once when activated, so there will be a second authentication.