How long you get, and what to do if you want longer
For most visitors, coming to Thailand involves no paperwork at all beyond a valid passport. The rules do change though, and they differ by nationality, so confirm the current position before you fly.
Do not rely on a forum post — or on this page — for a date or a figure. Entry rules and permitted stays move. A Thai embassy or consulate for your country is the authority, and checking takes five minutes.
Most nationalities receive a visa exemption stamp on arrival, valid for a set period, with the option of extending once at an Immigration office for a further stretch. For a two- or three-week trip you need to arrange nothing in advance.
Two things to have ready regardless:
If you already know you want more than the exemption allows, a tourist visa obtained before you travel gives you more room and avoids complications later. Extensions are also possible once you are here, at the Immigration office — Hua Hin has its own, which is far more pleasant to deal with than Bangkok.
Go early in the day, dress tidily and bring more photocopies than you think you need. There is a photocopier, and there is also a queue for it.
Overstaying is not a minor matter. It carries a daily fine and, beyond certain periods, a ban on re-entering Thailand. If your dates are tight, sort the extension before the stamp expires rather than after.
Immigration offices close on public holidays — worth checking against the holiday calendar if your deadline is near one.
We live here — ask us anything about Hua Hin and you will get the real answer.