Originally Posted by ajnaro
HOne withdrawal was from an account in Citibank NY, using a MasterCard debit card issued by Citibank, and the other was from Bank of Internet (BOFI), using a VISA debit card issued by that bank.
No magic here. First, as you note later, MC and Visa do have different exchange rates. The currency market isn't really like the stock market where everyone sort of agrees what the current price is. The currency market is a lot more dispersed, and depending on who you ask, you may get a different price. IME they're usually pretty similar, but a small fluctation is certainly not uncommon.
Second, I would guess that your Citi debit and BofI debit transactions posted on different days. 5/22 rate was 2.20, 5/23 rate was 2.26. Why does one post a day later even though it's an internal ATM? Who knows. It just happens that way.
RE: Citi, the exchange rate number they quote you should be with 0% commission. Then they tack on the 1% that you saw. This is if you use a Citi ATM. If you use a non-Citi ATM, they'll tack on 2%.