Can I use a pension certificate from the UK embassy for my retirement visa application in Thailand?

65+

I'm not entirely sure what type of pension you are referring too? If your in receipt of a state pension of being 65 years old or older, simply apply for an O-A visa in London on that basis. The UK is the only country that will issue this type visa on that basis and only applies to UK citizens. If your applying on the basis of being over 50 years of age but under 65 and not drawing a state but private pension, you will also need written proof of income from your pension provider. Signing a declaration only doesn't work for UK citizens and won't be accepted.

You will have a yearly pension advice from Min of Pensions - that will do.and it's free.

You use this website to get the verification of income from abroad notarized document from the UK consulate in thailand.

It is the ONLY document the thai immigration office will accept for proof of income from abroad. They do it ONLY by mail or email. You cannot walk up and get it from the consulate here

If your in the uk , why not apply at the Thai embassy , London , easy, I did mine there 5 years ago . Go to their web site and follow the requirements.

The UK has no embassies in the UK

You want to apply in the UK for the Non Immigrant O visa based on retirement OR do you want to apply at Thai Immigration Office while in Thailand?