I have done a search of this forum but can't find any topics/answers relating to this issue.

Can anyone tell me if one has to file a tax return in Thailand?

I have been living and working here for 3 years now, via a Thai employment agency. My monthly Payment Advice lists deductions from my gross salary for Income Tax and Social Security, and the remainder gets transferred into my bank account.

But I have never filled in a form, nor seen a tax return etc.

How can I prove (if indeed one day I need to prove) that I have been paying income tax on my salary here in Thailand?

5.  Tax Payment

      Taxpayer is liable to file Personal Income Tax return (Form PIT 90 or 91) and make a payment to the Area Revenue Branch Office within the last day of March following the taxable year. Taxpayer who derives categories of income (5) - (8) during the first six months of the taxable year is also required to file half - yearly return (Form PIT 94) and make a payment to the Area Revenue Branch Office within the last day of September of that taxable year. Any withholding or half-yearly tax, which has been paid, can be used as a credit against the tax liability at the end of the year.

Source: http://www.rd.go.th/publish/6000.0.html

Thanks very much Sumitr Man.

I will contact my employment agency to discuss the issue further.