Because the code is usually recorded when you leave your local area and stay for more than 4 hours after you reach your destination, and the local area will need to be erased on the 8th day after you leave the area for 7 days, it may be due to the lag in updating the information that will be updated on the next day.

Another reason is that the city is at the crossroads of administrative districts, and the signal from the base station may be out of whack in some cases, so the code may not be updated in time or accurately after 7 days.

Introduction of travel code:

The travel code refers to the communication big data travel card, the use of cell phone signaling data, through the user's cell phone is located in the base station location to obtain the travel record, so that you can accurately locate their own driving trajectory. The data of the "communication big data travel card" can be common in the whole country, and it can really achieve the comprehensive coverage of the whole country, and it can also query the international travel of my domestic cell phone number.

"Communications big data travel card" based on telecommunications big data, by the three major carriers to provide a unified interface, only have to fill out the cell phone number, authentication code and confirm my authorization, do not have to fill out the ID card number, home address, do not collect other personal information, the operation of the simpler and safer, to fully protect the user's privacy. For the country's 1.6 billion cell phone users to provide free query service, cell phone users can through the service, query my first 14 days to all the cities and towns information.