What is the best UK bank account for expats in Thailand to receive pension payments?

It’s worth watching the exchange rate, and transferring large amounts when it is favourable. Keep it until then earning interest. Revolut are good, as you can change to baht, but keep the money in the UK. Can do the same with wise, but they are not a bank.

Try Nationwide, they are apparently expat friendly.

I know there are Lloyd's bank accounts that you can use in uk and thailand and you dont need to be a resident in the uk. Check these out I did look at them recently and would fit your requirements, I beleive they are Lloyd's international but with i think it was 3 accounts with different levels in each

If you are looking to live in thailand I would check which accounts will allow you to keep them if you are not a uk resident as most will close your account once they see you are not a uk resident any longer

HSBC have what they call a Global Account. Get an Ordinary current with them and an online saver account. With there App you have them all linked together so do easy to transfer from one account to the other. The Global account has no charges and a good currency exchange rate. You need to check but I think you can transfer up to 50 k in one transaction. You also get a Global Account Debit Card.which you can use in Thailand in shops and ATMs. I have used them many times and I am very pleased with the account. Check all the information at your nearest HSBC Branch

Monzo is good.

Just keep open the UK bank account you already have. Transfer it when you need it.