Hypothetical situation. You have been in Thailand working for an educational institution for a number of years. You have a visa conditional on your employment. Suppose your old contract expired, say, on September 30 of this year and you were given a new contract. The new contract, however, was found by the educational institution's lawyers to be "illegal" and "unenforceable." Essentially, this would make your contract null and void. Question: wouldn't this also make the visa null and void? As you are technically no longer a holder of a valid contract, shouldn't you report this to immigration? And wouldn't you then have seven days to leave the country from the end of the last valid contract? Meaning, anyone still in the country would, in effect, have been on a visa overstay since 30 September?

Can I say what I think. You don't even need an "illegal" contract for your extension of stay (it is not a visa) to become invalid, it's enough that you quit the job.

Note, the 7 days are not automatic. You have to apply and pay Bt 1,900 when you cancel the extension for the reason above.

The new contract, however, was found by the educational institution's lawyers to be "illegal" and "unenforceable." Essentially, this would make your contract null and void. Question: wouldn't this also make the visa null and void? As you are technically no longer a holder of a valid contract, shouldn't you report this to immigration?

Fact is seeing as you have been on the same contract for a few years, you are not on a fixed duration contract, therefore the T&C's of your existing contract will roll over, until the "legality" of this "new contract" is resolved, this is not a "new contract" your dealing with merely a modification to your existing one, and until such time the new contract is signed your existing one remains enforceable. So don't panic, you don't have to do anything and immigration will not have a problem with this as regards extension.

For people working at the same place for a number of years under a 1 year renewal contract, the Thai courts have pretty much resolved this, although there is an appeal currently with supreme court, but the ruling basically says if your on a 1 year renewable contract and this contract rolls over for a number of years, you are afforded the same rights as a "permanent" employee of that company, the case originally was about paying severance, but this ruling would extend to employment contracts generally ie in the eyes of the labor law you are seen as "permanent" employee.