We put this question to some Thailand teachers on social media. As one teacher was quick to point out - legally, you can't work a single second of time without the correct visa or a work permit. However, as another teacher said - I would allow a maximum of three months. You're allowed to work on your single entry non-B visa, as long as the company can prove your work permit is in process. Another teacher kind of agreed by saying - legally you can't work without a work permit, but we all know that's unrealistic as many schools like to stall the process to make sure you've got what it takes to become one of their teachers. I'd also plan for three months.

This information comes from an ajarn reader.

It's common for schools to hang on to your teacher's license (both the permanent version and the version issued to that school for your current contract period) while you're working there.

Schools sometimes like to hang on to your passport and your blue work permit book too, officially for safekeeping, unofficially perhaps in an attempt to stop you disappearing at the end of the month.

Remember that your passport is yours, the school has no right to keep it and it should be kept with you.

The work permit has to be kept with you OR at your place of work during working hours: again the school has no automatic right to keep it in the school safe forever.

At the basic minimum, keep a copy of the work permit in case you need it to refer to the number or issue/expiry date.

When you leave your work, the school must give you your permanent teacher's license (but not the current one issued for your employment) whether you leave Thailand or remain to go on to a new job.

Check you have the original license with the original photograph and stamp on it. They have no right to keep the original permanent license and give you only a copy. It's yours, not theirs.

Don't overstay a visa in Thailand. It's as simple as that.

The overstay rules are getting stricter and stricter.

At best you will have to pay a fine depending on the number of days you have overstayed. At worst (if the overstay is a long one) you will be barred from entering the country for X number of years.

There's little point going into detail. DON'T OVERSTAY A THAI VISA. 

If you have a non-immigrant visa (possibly one that has been extended for a year) it will be cancelled if you leave Thailand.

So to avoid your visa being cancelled, get a re-entry permit from your local immigration office. 

This is very important if you have a work permit, because canceling your visa also cancels the work permit and you have to start the process all over again.

If you have a multiple entry non-immigrant visa which has been extended on a work permit (or you have a work permit application in process) then you still need a re-entry permit, because a new entry is considered to be a new visa, and everything will have been cancelled.

If in doubt, check with immigration first, because the consequences of getting it wrong are troublesome.

Very difficult to answer this question. You could take a cheap minibus from Bangkok to Aranya Pratheet on the Cambodian border and still have change from thirty dollars. Or you could fly to Singapore and stay a night in a swanky Orchard Road hotel.

Border runs can be tailored to fit most budgets.

Schools almost rarely/never pay for a teacher to do a border hop or consulate run.

The requirements can vary from embassy to embassy.

Decide which Thai embassy you are going to and then take a look at their website for the latest updated requirements.

If you are relying on a school to provide you with documentation, then the school should know exactly what is required.

A consulate run is when you physically need to get a new Thai visa in your passport and that means schlepping to a Thai consulate/embassy in a neighboring country.

It goes without saying that consulate runs are more expensive, more time-consuming (and dare I say more stressful) than border hops.

Depending on what time of day you arrive, Thai embassies / consulates will issue you a new visa within 48 hours.

A border hop means taking a train, a bus, a plane or anything with wheels, and crossing one of Thailand's borders to enter a neighboring country (Malaysia, Laos, Myanmar, etc). Then usually coming straight back into Thailand again.

A border hop is usually done to 'activate' a second or third entry on a double or triple entry visa.

Your work permit usually allows you to teach in ONE location only - the location written on the inside cover of the work permit.

However, several ajarn readers have informed me that it is now possible to add a second or other locations to a work permit book.

The main reasons that teachers work illegally (on tourist visas) are

1) they don't possess the necessary qualifications to obtain a teacher's license
2) their school / institute can't get them a work permit / won't get them a work permit / don't know how to get them a work permit
3) they actually prefer to remain a 'free spirit' often juggling around freelance work and not tied down to one particular establishment.

Be warned though: teaching without a work permit can land you in serious trouble. Jail / fine / deportation - take your pick.