Simply speaking, Vietnam visa on arrival is a process of getting an approval letter through a travel agency in Vietnam to pick up visa at any Vietnam airport upon your arrival.
What is visa on arrival?
This is an alternative way to get your visa to Vietnam. You just need to fill in our 'Online Application Form' on the website, pay the service fee, get your 'Visa approval letter' within 1- 2 working days and pick up your visa at one of your destination airport (Hanoi airport, Ho Chi Minh city airport, Cam Ranh Airport Nha Trang and Da Nang Airport)
After the agent obtains the approval letter for you, they will forward you a copy by email or fax (in your convenience). Copies of the same document will be forwarded on your behalf to Vietnam Immigration checkpoints at International Airports only. When you arrive in Viet Nam, the Immigration officers will have those documents ready and will be able to issue your entry visa quickly.
Please make sure that your surname, given names and entry/exit dates are correct. If you have applied for a multiple entry visa be sure that the approval letter states 'Is permitted to enter and exit Vietnam multiple times'. You will not be allowed to enter Vietnam before the entry date shown. The approval letter is valid at any of the three named airports but can not be used at any land border crossing. If entering via a land crossing you must already be in possession of a valid visa.
Print out the entire approval letter (color preferred but not essential) and don't forget to take it with you! Some airlines will ask to see the letter before they allow you to check in or board the aircraft and you will need it at the VOA desk when you arrive at the airport in Vietnam.
The agent will also send you Mẫu (Form) N1 - TỜ KHAI ĐỀ NGHỊ CẤP THỊ THỰC VIỆT NAM - application for a Vietnamese Visa, which is a 02-page document (this form is available upon arrival but you will usually have to queue to obtain it ).
Some other agents also have this form available for download on their websites. It is recommended that you fill in this form in advance (ignore the instructions about printing out two copies - only ONE is needed, irrespective of whether you're applying for a single entry or multiple entry visa).