The trip code is the same for two cell phone numbers under the same name.

Generally check the cell phone card used in the last 14 days, if two cell phone cards are used at the same time, then both cell phone cards can be checked.

Communication trip card through the cell phone signal location. By the China Academy of Information and Communication Research, China Telecom, China Mobile, China Unicom three major telecommunications operators jointly launched a trip query service on February 13 to open to the community, the user can be queried within 14 days to visit the situation free of charge. The data source of the location query service provided by the trip card is cell phone signaling data, which is obtained through the location of the base station where the user's cell phone is located.

The role of the trip code

The communications big data trip card is a query service provided by the China Academy of Information and Communications Technology (AICT) in conjunction with three basic telecom companies, China Telecom, China Mobile and China Unicom, to provide free query services for Chinese cell phone users using communications big data, which allows cell phone users to query the information of all the cities and municipalities that they have visited in the previous 14 days.

As of March 25, 2020, the cumulative query volume has exceeded 450 million times. starting from 20:30 on January 8, 2021, the trip card will no longer mark the names of cities and municipalities containing medium- and high-risk areas in red, and will be changed to include medium- and high-risk areas in the bracketed remarks after the city name, with the remarks serving only as a travel reminder and not associated with health conditions.

March 30, 2021, the national government service platform epidemic prevention health code has integrated communications big data trip card information, can be displayed in the health code users, whether they have been to high-risk areas and other trip information, help health code a code pass.