Very interesting data point, nkedel. FWIW, since the currency controls went into effect a year ago December and the onshore/offshore exchange rates diverged, using a Thai bank's ATM to withdraw baht has always given me the onshore rate, the one more favorable to someone selling dollars to buy baht. This has been true at Siam Commercial, Bangkok Bank, Bank of Ayuddya, and Thai Farmers (Kasikorn) Bank. (Haven't failed at TMB or Krung Thai, just haven't tried.)