also not correct, I'm on a non o extension live in TH more than 180 day's and pay tax, I don't know why people think TH is a Tax free country, it's all on the revenue website or just visit them. Some people don't have to pay tax some do, it depends on your personal situation.
Your Question is better answered by the Thai Revenue website, if you live here more than 180 day's you are a Tax resident, you pay tax on your income but every country is different.