Thanks, that makes sense. I don't think it matters all that much whether it's treated as income or savings because I won't normally be tax resident in Thailand anyway. I looked at the Saxo link but again it asks you for your country of residence and I don't have one (not tax resident anywhere, no right of residence outside the UK, spend no time in the UK, have no home there). The more I think about it the more the issue is not knowing what to put for that question / not knowing what the consequences would be if they decided, maybe several years down the line, that whatever I had put was wrong and the account should never have been opened. I can arrange to be resident in Thailand next year because I will be eligible for a retirement visa, but it's not clear whether this is really necessary just to open an investment account, and anyway it would just be for that one year. Might they come back and check I was still resident in a later year? What would they do if they found that I wasn't? In the meantime, would they report the income to the Thai tax agency, and would that cause a problem given I wouldn't be putting in a tax return? So many unknowns.