1. About Vietnam country code A country code, also known as an international subscriber dialing (ISD) code, is a telephone number prefix utilized in international direct dialing (IDD) to route calls to a country different from the caller's. Vietnam country code. To call to Vietnam use the international country calling code +84 followed by the national phone number you want to call. Vietnam is located in Asia and uses Dong. It has around 90 728 900 inhabitants, 10 191 000 landlines and 134 066 000 cell phone users. +84 Country code. Vietnam has various country codes assigned to it. The ISO 3166-1 numeric country code for Vietnam is 704. The ISO 3166-1-Alpha-2 or 2 letter country code for Vietnam is VN, while the ISO 3166-1-Alpha-3 or 3 letter country code for Vietnam is VNM. 4 days ago · 011 - international prefix; dial first when calling abroad from the US or Canada. 84 - Country Code for Vietnam. Phone Number ( remove initial 0) - 9 digits for mobiles and 10 digits for landlines. example call from the United States or from Canada to a landline in Hanoi: 011 84 24 ???? ???? 7AwHSG.