I had Tax ID before because I used to have Thai limited companies, I was the main shareholder, of course back in the day there was employee insurance etc, that was many years ago.
However, I closed those companies down in a correct fashion through a lawyer when I became ill..
So, this time I was starting afresh after many years of zero work in Thailand.
I still do some unrelated business in the UK and Cambodia. My UK income, I pay over there.
My Cambodian interest is taxed at source.
I don't do anything in Thailand apart from living here, and spending money which I transfer in from savings.
They said I was well under the threshold of the money transferred in and the allowances I am entitled to.
Not only that, but I am too young for pensions, so they were not in the equation.
They used my pink card and issued a new Thai tax ID based on that.