I am sure that you will need a multiple Vietnam entry visa as you will come back Vietnam after that. Do not contact the Embassy to chase your application (whether it has been received, processed and returned, by post or by fax), your enquiry will not be accepted, nor will the Embassy confirm the progress of processing. However, you may contact us for this purpose after a reasonable time only, e.g three weeks after the application is sent out.
Fill out the online form at http://www.smiletravelvietnam.com/travelvietnam/vietnamVisa.aspx. If you're traveling with a group, you have the option of applying for more than one person. We will ask you to give information such as your full name, date of birth, nationality, and passport number. You will also need to enter your Proposed Date of Arrival.
The Vietnam Embassy in Thailand is the only place in the Thailand that can issue a visa for Vietnam. But you can apply by post, using a form downloaded from the embassy website at the link below.
You should contact vietnam embassy in Thailand. you can find it:
you may contact us for this purpose after a reasonable time only, e.g three weeks after the application is sent out.