Fixed phone
How to call to Viet Nam (Fixed phones)
Like all countries in the world, with Fixed phones and mobile phone number
How to call the Fixed phones
-From overseas call: 84-area code-phone number
Code of Hanoi is 4
Code of Ho Chi Minh City is 8
Code of Thanh Hoa is 37
...
If the phone number you want to call is 34567321 (normal telephone number of Vietnam often have 8 digits, some provinces have 7 digits). The first number in the 8-digit number  is usually No 3
Then you will call as follows:
-If the call to Hanoi: 84-4-34567321
-If the call to Ho Chi Minh City: 84-8-34567321
If you have been in Vietnam, then you do not have to dial 84. You just have to click 04-3-4567321 (remember that the 0 at the beginning), Call to Ho Chi Minh City 04-8-34567321.