There are two applying options for those who have the Thai passport to enter Vietnam:
Vietnam Visa On Arrival is effective for citizens who are living far away from the Vietnamese Embassies and do not want to lose the issues (passport, money or documents) by postal mail.
Visa Administrative Institution: Vietnam Immigration Department
Processing time: 1 - 2 working days. In emergent case, you can get visa in 30 minutes.
Required Documents: No documents needed
How to apply: fill the form online at here Apply visa, wait for a confirmation Letter in a few minutes details when you will get the Vietnam Visa Approval Letter. Print your approval letter and take it with your trip. Besides, prepare also your passport + 2 photos + stamping fees Visa fees get visa stamp at Vietnamese airport.
If the Thai passport holders want to apply visa at Vietnam Embassy, they should to know that:
Visa administrative Institution: Vietnam Embassy
Processing time: depends on you how fast you need. But for sure, you should make a call to Vietnam Embassy for details.
Required Documents: passport, money and 1 new envelope with stamp on it and your exact home address in order to avoid losing issues.
How to apply: please take a look at contact information of Vietnam Embassy below
EMBASSY OF VIETNAM IN BANGKOK, THAILAND
Address: 83/1 Wireless Road, Lumpini, Pathumwan, Bangkok 10330, THAILAND
Phone: +66-2-515836/7/8 | +66-2-2517202 | +66-2-2513552
CONSULATE GENERAL OF VIETNAM IN KHONKHAEN, THAILAND
Address: 65/6 Chatapadung, Khonkaen 40000, THAILAND
Phone: (66) 4324 2190
Fax: (66) 4324 1154