Extended data:
Numbering principle
Towns and regional centers use two area codes. In addition to 1 area code (after 10), the three municipalities also used 2 1 or 22 area code. There are 24, 25, 20, 27, 28 and 29 central cities in Northeast China, East China, Central China, Southwest China and Northwest China respectively.
26 is a large foreign exchange area code reserved for Taiwan Province Province. It can also be understood that it is reserved for Taipei, because Taiwan Province Province is in East China in the administrative division order, so the latter is in the 25th district of Nanjing, the exchange center of East China.
Baidu encyclopedia-area code