Since UK embassy have changed process for passport are no longer in BKK. All the UK passport will processing in Hongkong.

One of my UK friend asked me buying banker's draft for passport fees.

Which currency that I should buy for passport fees, Pound, BATH, HKD?

According to Passport fees on UK embassy website

http://ukinthailand....passports/fees1

There are only Pound and Thai Bath fees.

Thank you for your advice.

you could have looked at the Bangkok Embassy website and followed the links for all the info you need :Payments for the new passport and the courier fee from Hong Kong if required, must be made either by credit card (click here to download a credit card authorisation form), or by International Banker’s Draft payable in Hong Kong Dollars (HK$) to “British Consulate-General Hong Kong”.

http://ukinhongkong.fco.gov.uk/en/help-for-british-nationals/passports/apply-from-se-asia/thailand/passport-renewals

Best and easiest way to pay is by credit card there is a seperate form for it with the application form and you pay for secure postage as well.

I got it all done in British Consulate Chiangmay.