Can't the four digits be used after Henan Telecom issued CXMYD# ID card?

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 the authorization reply Y, it realizes "roaming place inquiry", which can inquire the routing 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 everyone can inquire 10 times a day for free.

Note: If you can't query, this service may not be available in your area. Users can call telecom customer service for feedback.