Originally Posted by eigenvector

This is often repeated on FT and is good advice in general, but starts to fall apart in developing countries.

In Thailand, for example, ATMs charge extortionate fees to foreign cards and have very low limits to force you to pay the fee over and over. Exchange counters in the basement level of BKK (where the train is) offer rates within 1% of mid market which is better than what any international card network gives. You may have a bank that refunds these fees but most people don't.

In Cambodia many ATMs are not connected to debit card networks and will only give cash as a credit card advance, which will come with fees that dwarf any exchange rate spread from an exchange counter. Furthermore, you're going to be using a very small amount of cash ($15/day or less probably), which again makes any fixed fee proportionately very large.

My advice specific to these countries - bring USD and exchange it. You will get a better rate than the Maestro network and with no fixed fees. Just don't exchange a lot at the first place you see in airport arrivals if it doesn't have a good rate.