What should I do if the entry stamp in Thailand is less than the validity of my tourist visa?

She could probably still use the visa by leaving the country and coming back on it. Simple.

@Andrea *******

any responsible transport operator would wait for you if you had found out just after leaving immigration, there was a mistake with the stamp.

@Andrea *******

it's not a theory. I'm telling you a fact. There are NO cross border bus or van services between Thailand and Cambodia that use the Trat border crossing. You have to change transportation at the border. Hence why your statement "the bus wouldn't wait" (it wasn't even a bus because this route uses a minibus or minivan) makes no sense.

@Roberto ********

there's no cross border bus service at this border checkpoint, so unless she purchased a bus ticket before finishing up with immigration or bought a dodgy "thru ticket", which involves a change of transportation at the border from some travel agency in Koh Kong, then it's a strange comment to make.

That's because you have to change transportation on the Thai side. What this means is you only catch your minivan once you're done with immigration formalities and are ready to hail one. I'm sure there are hourly minivans or songthaews heading for Trat from that border. Isn't exactly a long wait and there are coffee shops, exchange booths and shops selling Vietnamese and Cambodian merchandise to keep you busy in the meantime.

@Andrea *******

It says you entered at Khlong Yai, which is in Trat. There are no cross border buses using that crossing, so I don't understand the part about the "bus not waiting for you ". You arrange your bus or minivan (most services between the border and Trat are by minivan; I haven't actually seen a bus ply this route before) once you're stamped into the country.

@Andrea *******

Did you show the immigration officer a print out copy of your visa? Was it an Evisa? Please post a photo of your stamp.

Reckon also you didn't look at the stamp while still there unfortunately; as that was the time to clear it up and correct this.

Seems like you were stamped in for a 45 day visa exempt if me maths is correct. 🙃

Until the visa validity date, you can leave and re-enter using the visa by showing the print out.

You might possibly be able to correct this at Chaengwattana office if you get a sympathetic officer...

YMMV

TIT