When in doubt, it is in your best interest to make a visit to a lawyer or the Ministry of Labor concerning your rights. You have nothing to lose (generally).

As far as the fixed date of the contract, I am aware of one school at only gives one, one-year contract. After that you just continue to work. There is an annual raise, but no new contract, at least not in English. I don't know if the myriad of papers signed for the extension and the work permit contain any contractual agreement.

If I recall correctly, there are conditions, at least in the Private School Act, about the amount of money that schools need to have in order to be licensed. A school should easily be able to calculate the amount of money they need for severance.

Again, check with a relevant legal authority and keep us updated.

How does one claim for severance if the company (A school in this instance) decides to not re-new a yearly employment contract. If you are on contract and the term of the contract is fulfilled by both parties I dont understand how one could claim for severance.

Thought so too, but obviously, you remark is going over everybody's heads.

Well, it's pretty simple (think some people have already explained it but here goes again): if you could write a contract in such a way to avoid paying benefits to 'full time employees' because they were only ever 'contract employees' then there'd be no company stupid enough in all of Thailand to have any 'full time employees' and no employers would have to pay any benefits. Genuine contract employees should ONLY be needed during a very specific and usually rather limited time period; not perennially (like teachers at schools). Since the whole point of the Labour Law is to protect employees from exactly this kind of situation, it is specifically stated that any employee after a certain amount of time (a few years, OP definitely qualifies) becomes a permanent employee by DEFAULT unless the position is eliminated through downsizing, etc. and it can be clearly demonstrated that the position is no longer offered. Obviously schools can't claim they don't need teachers, though the NUMBER of teachers may drop according to reasonable shifts in demand, and you would have to show that, say, you weren't firing Peter (without paying severance because the 'position was eliminated') in order to hire Paul (doing the same job but without the obligations and benefits established yet).

Since the employee is deemed a permanent employee, he is due the entire roster of labour benefits, including severance.

^ Nobly explained, IJWT.