If Vietnam really wanted to promote tourist...they would follow Thailand's lead and make visas easier and free. Just saying...
As above, EXCEPT:
E-visa is limited to 30 days AND only for those that are from countries approved for E-visa.
For those NOT on the E-visa list OR stays longer than 30 days OR multi-entry visas you need a Visa from an embassy/consulate OR a pre-approved visa letter that are for AIR arrivals ONLY.
AND, if you enter on a Visa Waiver you may NOT re-enter within 30 days without some OTHER form of visa.
There is NO such thing as a VOA for most people going to Vietnam.
Why people insist on calling a Pre-approved visa letter a VOA is beyond me.
There are regular visas (a full-page sticker in your passport), E-visas, Visa waivers, and Pre-approved visa letters. With a few rare exceptions if you don't have one of those you're not getting in.
They wouldn't let me fly out of Siem reap without the evisa
Of course they wouldn't. The airline will be fined and made to fly you back out if they let you fly to Vietnam when you didn't meet the requirements of Vietnamese Immigration. With a visa, E-Visa or pre-approved visa letter, you would have had no trouble at all.
for ex. through https://www. redacted .com/visa-service.htm
Do you have an interest in that company? Why suggest one that's so expensive when http://vietnamvisapro.net/ is only 40% of the price for the one you recommend?.
