If you have less than 15 days travelling in Vietnam, you can get visa at the airport in Vietnam. It is the easiest way to get entry Vietnam.
Visa Invitation letter Vietnam is also called VISA On arrival approval. This option is only applied for someone arrive to Vietnam by air. When arrive to any airport in Vietnam, you will be inline and wait for your VISA stamp at the Immigration Department at the airport. The time to get the visa is depending on the amount of people getting at the same time with you. It takes almost 15-45 minutes. This kind of visa is applied for someone travel in Vietnam for maximum 15 days and comes from the countries allowed by FOREIGN AFFAIR VIETNAM DEPARTMENT. Please see the list here.
To get your visa on arrival approval letter, please just contact Hanoi Tour Planner, send your photos of your passport and we will do the best for you. After maximum 1 week, we will reply to you and send you the VISA Invitation Letter. You just print it out and enjoy your travel journey to Vietnam