Colin - you must have had a Non Immigrant O visa at one time ... which it would seem you have Extended it for one Year - at least once. You can go to the Immigration office about 30 days before your current Extension of Stay Expires ... Then you apply apply again - using form TM.7, there are other requirements that you must have met the first time... Upon approval you get another One Year Extension of Stay (based on being over age 50 - some times said as 'for Retirement') ...

Go to a local immigration office - Single Reentry Permit 1000 Baht

With a Multiple Entry Visa -- you can go out and back in as often as you can afford the travel - That is what the M stands for... But -- when you exit and reenter just before the 1 year expiry date -- that is the last 90 days you can get ... then within those last 90 days ... you have to buy a reentry permit to go out and back in

My point is Money Talks in Thailand and without paying large sums getting a Non B and Work Permit even for a Registered Business owner is an ordeal. And some of the money involved may not have been for legitimate fees.

And what large amount did you pay ... 50,000 THB?

And Chiara I bet you got a BIG Bill from the agent who formed your company and got the Non B and WP

Krabi allows 45 days

Thale Ban National Park is in Khuan Don District and the Thai Border Checkpoint there is named Wang Prachan... The Malaysian checkpoint on the other side is called Wang Kelian - just for information purposes.

The other fairly nearby Satun Border crossing is from the Tammalang Pier about 8 kilometers from Satun city center. From there one goes by ferry to and returns from the Kuan Jetty on Langkawi (island), Malaysia - checking in and out of Border Immigration Services. Trip time each way is about 1 hour and 20 minutes.

I don't have any information as to whether this method of entering Thailand or doing a border bounce falls under the same rules that have been described for Thale Ban National Park in Khuan Don District.

Clarification Marco... by Satun do you mean the one in Satun city or do you mean the one also in Satun Province at Thale Ban National Park. In my area of Krabi people are constantly confusing the two border checkpoints. I assume you mean Satun city (Muang Satun) but I wanted to be sure.

I just checked your place of residence, the closest place for you to apply for the O-A visa is the Thai Embassy in Washington, D. C. You can make a visit there but you should be able to do it by mail. Check that Embassy 's website.