This is what I was wondering (about dual-tax treaties). For example, if you have savings income or an occupational pension income that is not sourced in either Thailand or your home country, but from a third-country, and you aren't paying any tax in your home country, can you just "refer" to the dual-taxation treaty with your home country? Or will they (Thai Revenue Dept) demand to see a tax return from your home country before letting you off the hook for Thai income tax? Aside from the US, most Western countries base their tax demands only on their nationals if they are 'residents' there. So many unknowns. But pity the farang pensioner here that is about to lose 15-25% of his small pension income. If he's living too close to the bone, he may need to leave. And if his only home was here (maybe bought a condo) then he's truly f'd?