Currency UK only list the major world currencies on their on-site currency converter so, like you, I wondered whether they also did our local currency (THB). They do. I think they do just about everything - maybe I should give them the heads-up to get themselves a better currency converter for their site.
I know we're affiliated with them via BE but we use them personally too and have been more than happy with their service. They held our hands through the process the first time (when we were transferring funds to buy property) as we weren't sure of what we were doing. They respond very quickly to emails and give good customer service. I'm sure if you emailed them about their spreads they'd be happy to answer.
(Our offshore bank, AIB, wanted to charge us 5% of the value of the transaction! So, I repeat, be very careful of doing currency exchanges via banks.)
I admit that we looked at some other for-ex services and shopped around the next time we wanted to do a big transfer, but we just never had the confidence in the others we looked at (mix-ups and not very good customer service) so we went back to Currency UK again.
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