If your stamp has expired you will need to leave the country and pay overstay.

If you are a tourist stamp you may be able to pay the fine and extend the remainder of the 30 days.

Without knowing what visa it's impossible to tell you the exact options.

@Chrisna *********

it absolutely applies, free work or volunteer work in these fields is prohibited.

You cannot do the work of a Thai.

You can only extend non-o 1 year and the 1st extension must be for the reason you obtained it.

If you are married to a Thai or have a Thai child you can get a visit Thai family 60 day extension 1 time.

I'd you obtained it for any other reason you can only extend 1year.

No, you cannot conduct any form of business inside Thailand.

The deposit will be lost.

There will be no court.

Nothing can happen thru Immigration. It is not a criminal case.

The agent will rent the property out again.

@James *******

sorry your opinion is incorrect.

If the course is paid for like any tour it is up to you whether you attend or not.

Remember even music festivals can be used to get this visa.

ED visa and Volunteer visas were fraudulently obtained and are orchestrated by agents and services in Thailand.

And are proving to be problems.

But these types of Visas are regulated and still happen.

The DTV with the "soft" power is to encourage tourism, not education.

No different than buying a gym membership and never going, you still had a gym membership.

Fear mongering based on your opinion with no factual basis is not in character for someone generally well versed in Thai visas.

Disappointing.

@James *******

there is no requirement to attend or any enforcement as it is a leisure activity only.

You are given the visa with no requirement to check in or extend anything in country other than 90 day reports and tm30.

Yes its ridiculous.

If needed enter as a tourist then start the process with agent.

With an OA which is multi-entry, if you have insurance to cover it, you would be given another 1 year stamp.

Effectively the 1yr OA can be stretched to almost 2 years with strategic exits/entries.

However the 2nd year is not multientry.

During the second year you can extend in country to yearly extensions.

However you will require the funds in a Thai bank AND always required the mandatory approved health insurance.