To use visa on arrival to Vietnam, firstly, you need to submit the online application for a letter called “visa approval letter”. It is issued by the Vietnam Immigration Department (belonging to the Vietnam Ministry of Public Security) as an official permission allowing person(s) having name(s) on it to get on flight and have visa stamped onto passport upon arrival at the Vietnam airport. If the travelers decide to use visa on arrival, they cannot get on flight without this approval letter.
Here is the sample of a visa approval letter:
To apply for a visa on arrival now, please click here.