I did it yesterday. Easiest way is to use a minibus service specifically for the border bounce. Otherwise take a Green Bus from Arcade Bus Terminal 3 to Mae Sai and then a songthaew to the border. Then go to passport control on the Thai side of the bridge, show them your passport, cross the bridge into Myanmar, cross over the road to a small immigration hut, give them your passport and 500baht (or $10), if you don't want to go shopping an official will take you to another hut across the road, they stamp you out of Myanmar, then cross the bridge again into Thailand, go to immigration there, fill in the arrival/departure card (you'll probably have to ask someone for a card), take it to the passport control. Welcome back to Thailand!

@Jacco **********

"Your holiday has been long enough" is not how immigration officials think - they think "what are the rules" and "which part of the rules do we actually need to enforce".

I guess I should have added a winky smile to make it clear

Why does she need to get the stamp corrected? It's obviously meant to be stamped 2017. As long she exits by the date in 2017 there's no problem, right? I ask because the same thing just happened to me!

I've just had the same thing happen to me. 30 day entry expires June 2018.

The visa is cheaper than the exempt extension, but you have to factor in the cost of traveling to a Thai consulate (and maybe accommodation) to get a visa. This usually makes the exemption extension much cheaper.

No. She'll get a 30 day visa exemption. Visa on Arrival is only for citizens of these 19 countries

No. You don't need to ask for anything. Your passport will be stamped with a 30 day entry permit (a visa exemption). (I'm assuming you're South African).

You can only get a tourist visa from a Thai Embassy outside Thailand.

Simplest thing is take a Green Bus to Mae Sai, go over the bridge to Myanmar, turn around, re-enter Thailand and take the bus back to Chiang Mai . You'll get a 30 day exemption which can be extended. I'm doing this myself on Tuesday as my current visa exemption also expires then. You can do the land entry visa exemption twice per calendar year.