Getting pesos out of a wall in Mexico City or Cancún is easy — the surprise is usually on your bank statement afterwards. ATMs across Mexico are plentiful, reliable and connected to the major global networks (Visa, Mastercard and Amex), so almost any foreign debit or credit card will work. A handful even dispense US dollars alongside pesos, though that's rare, and some machines also handle deposits and bill payments for local customers.

For Mexican cardholders, cash is cheap: using your own bank's machines (or its affiliated network) is generally free within your account limits, with some banks offering a set number of free withdrawals per month. The costs kick in for foreign-issued cards.

If your card comes from a bank outside Mexico, expect a stack of possible charges. The Mexican ATM operator adds a fixed fee — typically around 100 pesos — which is shown on screen before you confirm. On top of that, your own bank may apply a foreign transaction fee, and there's the exchange rate spread: banks don't give you the wholesale rate you see quoted online. That hidden margin usually runs 2% to 5% of the transaction. Use a credit card and it gets worse — cash advances often attract interest from the day of withdrawal, regardless of whether you later clear the balance, and the fee structure differs from ordinary purchases.

A worked example shows how it adds up. At a wholesale rate of 18 pesos to the US dollar, a 5,000-peso withdrawal should cost about US$278. In practice, with the Mexican ATM's fixed fee plus other bank charges, you might see closer to $295 debited — an effective rate of around 17.28 pesos to the dollar, roughly 6% worse than the headline rate.

Despite all this, ATMs remain the fastest and most efficient way to access local currency from a foreign account in Mexico — withdrawing over the counter at a bank or exchange house can attract even more charges. A few practical habits help: decline any on-screen currency conversion and always choose to be charged in pesos, take out larger amounts less often to dilute the fixed fee, and check your card issuer's overseas withdrawal fees before you fly. And if you do use a credit card for cash, know that it's usually the most expensive option on the menu.