How to query roaming information in 15 days?

Specific ways for the three major operators to inquire about roaming places:

China Unicom: The mobile phone sends "the last four digits of CXMYD# ID card" to 100 10 to inquire about the information of domestic roaming places in recent 30 days, which is convenient for rework and auxiliary investigation.

China Telecom: The mobile phone sends "the last four digits of CXMYD# ID card" to 1000 1, and after authorizing to reply Y, it realizes "roaming place inquiry", which can inquire the route information of the mobile phone number in the past 15 days.

China Mobile: The mobile phone sends "the last four digits of CXMYD# ID card" 10086, and then inputs the last four digits of ID card according to the reply message, so that the provinces and cities visited in the past month (no cities) can be inquired, and each person can inquire 10 times a day for free.

Note: If the sent instruction cannot be inquired, it means that this inquiry service has not been opened in this area. Users can call the operator's customer service to find out.