@Paul **********
You can apply for over 50 Non O at UK Thai Embassy. Just select Retirement from the list and it takes you to Non O application. You will get the 90 days and then you have to meet the requirements when in Thailand to get the 1 year extension (800k in bank).
Or
Apply for O-A but you get the full 1 year on entry and financial requirements are UK based.
We recently did O-A, AXA were cheapest for basic policy but we went with another. If you go AXA, you will need at least 2 weeks to get the policy, very slow compared to others.
Also, do the DBS check, quicker and cheaper than ACRO.
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-non-immigrant-visas