I am from the UK, I have pensions (State and SIPP) that I draw down into Thailand. I live permanently in Thailand (i.e. I do not have any home in the UK).
I have read the DTA applicable to the UK (You can find it here: https://www.rd.go.th/english/766.html)
According to this DTA (Article 4, Fiscal Domicile) I am a tax resident of Thailand. That is, my Contracting State is Thailand.
Now, according to Article 16, 'Dependent personal services', of the DTA, my income (aka my employment) is exercised in the Other Contracting State, which is the UK. Paragraph 1 states that such remuneration may be taxed in the UK. And it most certainly is, of course. Nowhere does it state that I will be taxed in Thailand UNLESS, if I understand paragraph 2 correctly, I live in the UK for up to 183 days in a fiscal year.
I have typed out Article 16 below, with my interpretations on what is meant for Contract State and Other Contracting State as it applies to me. As far as I can decipher, i am NOT expected to pay tax in Thailand. However, I WILL be applying for my Taxpayer Identification Number next week, and I will get prepared to submit a Return if necessary.
Article 16
Dependent personal services
Subject to the provisions of Articles 19 (Governmental services) and 21 (Teachers), salaries, wages and other similar remuneration derived by a resident of a Contracting State (THAILAND) in respect of an employment (I am including pension here) shall be taxable only in that state unless the employment is exercised in the other Contracting State (UK). If the employment is so exercised, such remuneration as is derived therefrom may be taxed in that other State (UK).
Notwithstanding the provisions of paragraph (1) of this Article, remuneration derived by a resident of a Contracting State (THAILAND) in respect of an employment exercised in the other Contracting State (UK) shall be taxable only in the first-mentioned State (THAILAND) if:
The recipient is present in the other State (UK) for a period or periods not exceeding in the aggregate 183 days in the fiscal year concerned; and
The remuneration is paid by, or on behalf of, an employer who is not a resident of the other State (UK); and
The remuneration is not borne by a permanent establishment or a fixed base which the employer has in the other State (UK)
Notwithstanding the preceding provisions of this Article, remuneration in respect of an employment exercised aboard a ship or aircraft in international traffic may be taxed in the Contracting State (THAILAND) in which the place of effective management of the enterprise is situated