@John *********
there you go I agree with you. Pretty simple process if you've already paid the taxes on your income, you do not need to go through and pay taxes on the same income again. I am from the United States and if Thailand notifies me that they want to know about my income, I will certainly bring my American tax return returns to their offices. As I have not heard anybody having to do this, I do not believe it is necessary. In addition, I have heard of people going to the Thailand Tax office is looking to get a tax identification number and being greeted with disdain by the officials in the office for their unnecessary inquiry. There is a financial motivation for accountants in Thailand to get people to file taxes twice, even though it is not necessary.