existChina MainlandWhen making a domestic long-distance call, you must first dial the long-distance prefix —— 0. For example, sinceShanghaiMake a long distance call toBeijingWhen you need to dial the long-distance prefix 0, the Beijing area code (transit area code) 10, and the telephone number. In Mainland China, if you want to make international long-distance calls (includingHongkong、MacaoandTaiwan), you need to add the international prefix "00", followed by the international area code, transit area code and user phone number to connect. When calling from overseas (including Hong Kong, Macau, Taiwan) to mainland China, the local international prefix, international area code (86), transit area code, and user phone number are used. For example, if you want toAmericaWhen dialing international calls directly to Beijing, China without relying on an operator, you must dial the local international prefix 011 or, China’s international area code 86, Beijing area code 10, and telephone number. The switch structure of the People's Republic of China adopts a four-level tandem to radiate long-distance telephone network.
- Office C1 is a regional central office or a foreign exchange, established in 8 major cities:Beijing、Shanghai、Shenyang city、Nanjing City、Wuhan、Chengdu、Xi'an、Guangzhou City
- The C2 bureau is the provincial central bureau, established in the capital cities of the provinces other than the C1 bureau.
- The C3 bureau is the regional central bureau.
- Bureau C4 is a county-level exchange center.
In terms of structure, C1 bureaus and municipalities use two-digit area codes, Beijing is "10", and other regions start with "2". The three-digit area code is used for other districted cities in various provinces, autonomous regions, and municipalities.