Simply speaking, visa-on-arrival (VoA) is a process of getting letter of approval through a travel agency in Vietnam to pick up the at Vietnam airport upon arrival.
Yes, it is! The visa approval letter is issued by the Immigration Office, so it a legitimate document. "Visa on arrival" is also stated in the Immigration Laws of Vietnam Article 24, 1999, clause #6, Chapter II.
The Immigration issues a letter of approval for whom wish to visit Vietnam. As the whole application process can be completed online, this saves a trip to the Vietnam embassy and the sending in of your passport to the embassy is not required.
Once approved, applicants will receive their approval letter by email, which is recognized by all airlines traveling inbound to Vietnam. Print it out, fill out the "Entry and Exit Form", prepare passport, 2 passport-sized photos. Show them and pay Stamping Fee to the Immigration officer when you arrive at the Vietnam airports to get your visa stamped.
This video below is tutorial to show you how to apply for a visa-on-arrival to Vietnam.
#1 - No visa on arrival without applying online: many people think that they can get a visa directly at Vietnam international airport without applying online. That is NOT true, you may end up with delaying/cancelling your flights or waiting at the airport until the visa is approved. So, you will need to apply online for an approval letter in order to pick up your visa at Vietnam airport.
#2 - Visa extension: many people think that it is easy to extend a visa once they are in Vietnam, however, in fact, it is not that easy, and extending a visa may be a costly and time consuming process. So, if possible, just apply for a 3 month visa in advance instead of a 1 month one to save money on visa extension.
#3 - Spelling / Typo mistakes: Many applicants fill in the Application form with WRONG details: full name on passport, passport number or date of birth. Normally, that may not be a big problem, however, in some cases; they will be refused by the airline at the departure airport since the information on the letter of approval does not match those in the passport. So, make sure you enter everything correctly and carefully.
#4 - Visa on arrival at the border: Visa on arrival works for air travel only, it means there is NO on arrival visa for overland/border crossing or sea/water entry. So, in case you DO NOT enter Vietnam by air, just make sure you have the visa in advance.
#5 - Arrival date: many people think that the visa validity will start from the date they enter Vietnam, not from the date they provide, however, it is NOT. The visa validity will commence from the date you provide in advance, not from the date you will enter the country. So, just make sure that you make a clear plan of when to enter before ordering a visa to Vietnam.