Hi. I live in Phuket and have a 6 month triple entry tourist visa.I understand I need to do a visarun every 2 months. Do I have to go to Malaysia or Myanmar etc. or can I just go to the immigration office here in Phuket because I have a triple entry? Not sure how it works. Thanks

You don't have to leave every 60 days. You can apply for a 30 day extension at immigration. After that you will have to leave the country and re-enter to use another entry from your visa.

You can do a border run to Malaysia or Myanmar to get the new entry.

So Basically I can get 3x90 days in total? Im just scared if I extend it my triple entry visa wil become void and then I will need a new visa?

Getting extensions of your entries has no effect on your visa. They certainly do not make it void.

The only thing you have to watch for is the enter before date on your visa. You must use the 3rd entry on or before that date.

It is possible to get almost 9 months of total stay from a 3 entry tourist visa.l

Don't confuse the visa expiration date, printed on the visa you got from some embassy or consulate, with the permission to stay expiration date on the hand stamp put in your passport by Immigrations in Thailand or on your arrival.

The expiration date of the visa is not extended or renewed. As stated above you must make your 2nd and 3rd border crossing into Thailand before the expiration date on the visa sticker.

Depending on your timing, in theory you could get a 60 day permission to stay when your first arrive in Thailand and a 30 day extension of that permission by applying at an immigration's office in Thailand. Then you do the border crossing to repeat that process a 2nd and 3rd time. You can apply for each 30 day extension a week or two before your current permission to stay expires. You won't lose any days since they add the 30 days onto the end of your 60 days, but when you do a border crossing, the new 60 day permission to stay starts from the date of the crossing.

Towards the end of all this, your visa will have expired/be marked "used," but you will still have time left on your permission to stay, which is all you will need to remain in Thailand legally ... until the final permission/extension of stay expires.