How to send messages to Laos in China?

The number is 00856 (Laos country code)+Laos mobile phone number. If you call Laos' mobile phone from home, you need to open the international long distance function.

Relevant appendices:

Country code (or country code) is a set of geographical codes used to represent countries and overseas territories. The country code is a series of short letters or numbers, which is convenient for data processing and communication. There are many different national code standards in the world, among which ISO3 166- 1 is the most widely known. The country code can also refer to the country code of international long-distance calls, that is, the international telephone area code of the International Telecommunication Union (E. 164).