Some great advice on here, but is it possible to have a Thai version of what's needed for uk visit visa. 

Uk gov website and should be able to change from english to Thai?? I think.

It's quite a few pages but in general easy to follow.

Main points they are looking for are reasons for the Thai girl to return to Thailand and well documented evidence of the relationship.

After filling in all the pages and gathering supporting documentation your girlfriend has to make an appointment at the VFS office to submit everything and have biometrics done ( photo/fingerprints ).

Once that's done there is up to a 15 day wait for approval/rejection.

If she gets the visa and you have stated say a four week holiday and on arrival you/she decides to stay longer make sure you e-mail visa services and tell them how long. The 'visit' visa may be valid for 6 months but overstaying the time stated on the application might cause problems for future applications.

PS.

VFS don't make the decision, they just forward all the paperwork.

Edited December 28, 20196 yr by overherebc

This is an English language forum aimed at native English speakers, but, as overherebc suggests, there are instructions available in Thai.

 

https://www.vfsglobal.co.uk/th/th/how-to-apply