3 hours ago, Liverpool Lou said:

I've no idea, why are you asking me that?  I didn't say that he had one fiver, or coins.

Currency exchange booths don't accept coins. Unless the gent only had (or needed) enough for maybe a beer and noodles is it not likely he did/does have a bundle of GBP?

go online and check out one of the banks, ala Bangkok Bank, and Superrich.  Check out for yourself the difference in exchange rates.  Usually superrich exchange rate is better than any of the banks.  This is very simple to do.