After changing the phone number on the Health Kit, the travel history of the previous number still need to be checked for seven days starting from the date of changing. After these seven days, the previous number will be deleted from the "Personal Center" and it will no longer be checked. Users can check the status of unlinked but not yet deleted phone numbers in the "Personal Center". Previously linked numbers and the days until deletion will be displayed in gray. To make sure that your Beijing Health Kit functions normally, please change the phone numbers to be deactivated in time.

(Source: Official website of the People's Government of Beijing Municipality)