There are many area codes for landlines, as well as a separate format for mobile phone numbers.

The five emergency phone numbers are 111 (child protection), 112 (lifesaving services), 113 (police), 114 (fire), and 115 (first aid).

[1][2] In Vietnam, mobile phone numbers follow the format 09x-xxxxxxx or new prefixes: 03x, 05x, 07x, 08x.

All 11-digit numbers with prefixes '012' of VinaPhone and MobiFone, '016' of Viettel, '018' of Vietnamobile and '019' of GMobile will be converted into 10-digit ones.

To minimize possible loss of communications before, during and after network code change, each stage must consist of four steps as follows: In Communication of 31.V.2018 the Ministry of Information and Communications (MIC), Hanoi, announced a change on mobile telephony services, where all previous telephone numbers starting with 012x (mobile telephony services numbers) are moving into the other mobile number areas (e.g. to 07x or 08x etc.).