You can apply for a new extension of stay at your local immigration office 30 days before the current one is due to expire. In some places (Bangkok, Phuket, Chiang Mai, Buriram) you can even do it 45 days before. You don't lose anything by applying early (as the new extension starts after your old one expires) and doing so early allows you to handle any expected or unexpected problems.

@Gregory ********

Nope. If you meet the requirements for either extension you can apply for an annual extension year after year. You never have to leave Thailand.

If you want to leave Thailand you merely get a Re-Entry Permit (either from Thai Immigration, my recommendation, at a cost of 1,000 baht for single re-entry or 3,800 baht for multiple re-entry; or you can get from the airport before you leave, although that would make me too anxious ;-) ).

@Darren ******

I updated my post to reflect the new information you provided. Thanks, for bringing that information, which was new to me, to my attention. I learned something.

Is this a business visa available for employees of companies that are registered with the Board of Investment (BOI)?

@Darren ******

Did you write: "As others have said, Elite Visa" or not? Do you understand that the Elite Visa doesn't allow one to stay in the country without having to exit the country or check-in with and pay annual fees to Thai Immigration? Those aren't trick questions.

When I get something wrong, which happens more than I'd like, I try to learn something from the experience. When someone tries to point out that I made a mistake I take it seriously and if I'm wrong I will try to correct the mistake. Especially, if there's a possibility that someone could be seriously misled by the mistake I made.

@Darren ******

If you think the Thai Elite Visa allows one to stay in the country without having to exit the country or check-in with and pay annual fees to Thai Immigration you are simply mistaken. When you write, "As others have said, Elite Visa" you are mistaken. It doesn't allow you to do that. Many people were caught out by that mistaken understanding and it seems worthwhile to me to point that out very clearly.

If you have an Elite Visa and you stay in the country past when your permission to stay is valid, unless you leave the country or get an extension of stay at Thai immigration, you will go on overstay. That's a pretty serious consequence.

When I see someone who is unaware of that requirement for Elite Visa members I try to correct that misapprehension because I don't want to see someone fined 20,000 baht, deported, and banned from entering Thailand. That seems pretty serious to me.

@Darren ******

The Elite Visa is not a visa type that "allows for the longest continuous stay without having to exit the country and/or check-in with and pay annual fees to Thai Immigration. So your statement was incorrect. I was pointing that out.

I still don't see where I have said anything wrong in my replies in this thread and you seem to find it difficult to articulate what it is that you think is wrong.

@Darren ******

Sorry, that doesn't answer my question as it has nothing to do with anything I wrote.

@Darren ******

I've re-read my answer. What specifically about my answer is wrong?

A marriage extension is also available. A little more hassle (you typically have to wait for it to be approved by the district office, so often you have to report back to immigration to actually get your extension) but only 400,000 baht required and it can be used for the rest of the year (outside of seasoning requirements during which the 400,000 minimum balance must be maintained) unlike the retirement extension.

Both are superior to the Thai Elite Visa for the person who wishes to stay in Thailand long term without having to leave every year.

@Darren ******

Link to it please and I'll have a look.