For the past umpteen years I have used the "yellow bank" ATMs. I always got a near-current exchange rate (a 1% currency conversion fee) and it allows a daily withdrawal of 30k baht. The service fee (200B) has always been refunded by my bank back home, so I was always happy.
Last night, for the first time, a new screen appeared just at the very end of the ATM withdrawal process which asks if you want THEM to do the conversion to US dollars? I foolishly pushed "ACCEPT" which was a BIG mistake -- the receipt slip informs me that they took an additional 5% currency conversion fee for the privilege of doing the conversion!! This means I lost more than $40 on that transaction! I am really pissed!
I knew the moment I pushed ACCEPT that I had made a mistake, but there is NO WAY to cancel or reverse your choice once you push that button (which is far bigger than the other buttons). I was in a hurry and it cost me dearly.
So please, any Americans out there, please be careful with this raunchy (at best!) business practice. I was going to go back to the Yellow Bank to complain this morning but I realized it would do me no good. SO please be careful! (I don't know if this scam, and yes it is a scam, is also being done for pounds and euros, I hope not.)