I'm thinking of paying a monthly fixed amount into the SET50, which I believe is operated by the Thai Military Bank.

Does anyone here do it and would it be any cheaper to do it directly through the bank rather than through my Maybank account?

Starting to think of my retirement in 20 years as I'll not get one from the UK.

The SET 50 is an index. You can't buy it directly.

There are funds based upon the index but, after charges, they return less than the index.

There are also ETFs based upon the index which typically have smaller ongoing charges, but still return less than the index.

And you can't buy through your bank, though your bank may well have an associated brokerage in the same financial group. E.g. TMB Asset Management and TMB the bank.

And you have to ask yourself whether, given the level of corruption in Thailand. you're really better off buying a product that tracks an index (and paying the cost of that corruption), or buying an actively managed fund which (if you're lucky) avoids much of the performance detracting corruption.