Thailand dividend tax rate is not a flat rate of 10% ???? that is only withholding rate at the time of distribution. Your effective dividend tax rate will be whatever your highest tax rate will be. in most cases, you would ending up paying 35% in dividend tax since Thailand income tax is very high compared to western countries (their 35% tax income rate starts at super small threshold of USD 120k which is a joke, it should be at least USD 500k for that kind of tax rate).