Why everything is paid in pesos
Mexico runs on pesos, and that simple fact has more consequences than it looks. Plenty of tourist businesses in Cancún, Los Cabos or the Zona Rosa will take dollars, but at an exchange rate they set themselves, which is usually a good deal worse than the bank's. Paying in dollars at a shop counter means, in practice, accepting an invisible commission of ten or fifteen per cent. Changing money at the airport has the same problem, with the added detail that the exchange desks there know the traveller has just landed and has no real alternative.
The sensible way to get pesos is to withdraw them from a cash machine with a debit card, once you are in the country, and to do it in a few large operations rather than many small ones, because almost every fee is charged flat per withdrawal. Bringing some cash from home as an emergency reserve does no harm, but there is no need to arrive with a wad of dollars. And it helps to accept from day one that part of the trip is paid in notes: the market, the village taxi, the tip, the bus-station toilet.
Which machine to use, and which to skip
Not all cash machines are the same, and the difference shows up on the statement. Machines inside or attached to a recognised bank branch charge moderate fees, usually sit under cameras and a guard, and if one swallows your card there is somebody to complain to during office hours. Standalone machines from brands you only ever see in tourist zones, convenience stores or hotel lobbies work on a different logic: a high fee per withdrawal, a low limit per operation and a screen designed to get the traveller to accept the machine's own exchange rate.
The practical rule is simple: withdraw in daylight, from a machine inside a branch, and preferably in a city before heading to villages where there may be none at all. The machine's own fee usually runs $2 – $6 USD (2025) per operation, on top of whatever your home bank adds, so taking out the maximum allowed in one go works out far better than four small withdrawals. Per-operation limits tend to sit between $250 – $500 USD (2025), depending on the bank and the machine. Telling your bank you are travelling avoids a security block on the first attempt.
Fees and the conversion trick
A single withdrawal in Mexico can carry up to three separate charges, and it pays to know them. First, the machine's own fee, announced on screen before you confirm and usually around $2 – $6 USD (2025). Second, your issuing bank's foreign-transaction fee, which depends entirely on your account and is sometimes zero. Third, a percentage currency-conversion loading that many banks apply to the total. Added together, a small withdrawal can cost an absurd share of itself; the same charges spread across one large withdrawal are barely noticeable. The arithmetic argues for fewer, bigger trips to the machine.
The fourth charge is the avoidable one, and it takes the most money. At some point the machine's screen, or the card terminal in a restaurant, asks whether you would like to be charged in your home currency instead of pesos, showing a friendly figure and an exchange rate of its own. That option is dynamic currency conversion, and it is always worse than letting your own bank do the converting. The correct answer is to refuse: continue without conversion, or simply pay in pesos. The screen sometimes asks again in different words, and you say no again.
The small-change problem
The five-hundred-peso note is a logistical problem. Cash machines hand them out cheerfully, and much of Mexico does not want them: the woman selling quesadillas, the village taxi driver, the fruit stall in the market and the shared minibus all run on coins and small notes, and breaking a big one at eight in the morning leaves somebody working on tiny margins with no float. The usual reply is not a flat refusal but a polite no tengo cambio, followed by an awkward wait while the seller goes off to ask the neighbouring stalls.
The fix is as silly as it is effective: turn big notes into small ones where it does not hurt. An OXXO, a supermarket, a petrol station, the ticket window at an archaeological site and the hotel front desk will all take five hundred without blinking, especially on a purchase of some size. It is worth leaving each morning with twenties, fifties and hundreds, plus loose coins for tips, public toilets and the lad who helps with the luggage. Anyone travelling by bus is also glad of change for station coffee and the taxi at the other end.
Where cards work and where cash rules
Cards work in more places than people expect, and in a few that matter they do not work at all. Hotels, chains, supermarkets, large petrol stations, museums, city restaurants, airlines and the ticket counters of bus lines such as ADO take cards without fuss, and contactless payment is widespread in the cities. Outside that perimeter the cash country begins: markets, fondas, street stalls, local transport, taxis, entry to cenotes and swimming spots, village crafts, tips, and more or less anything costing less than a hundred pesos. The line between those two worlds is sharper than most visitors assume, and it barely shifts from one town to the next.
Two details get learned the hard way. The first is that accepting cards and having a working terminal are not the same thing: the signal drops, the machine will not connect, and the business asks for cash quite matter-of-factly, which in a village with no bank becomes a genuine problem. The second is that some small places add a surcharge for paying with plastic, usually between three and five per cent, announced on a handwritten sign beside the till. Carrying enough cash to cover a whole day, every day, quietly solves both situations before they happen.
The mistakes people keep making
The expensive mistake is not taking cash out but taking it out badly: small, frequent withdrawals from airport or lobby machines, with the on-screen conversion accepted on top. Three or four operations like that in a week can cost as much as a hotel night, and the whole expense is avoidable with two decisions taken before leaving home. The second classic error is arriving with a wad of dollars intending to change them as you go: airport exchange desks apply poor rates, and plenty of smaller cities have nowhere obvious to change foreign currency at all.
Then come the mistakes of distribution. Carrying one card and all your cash in the same wallet works right up until the day it does not, and at that point the trip becomes genuinely difficult. Split things up: one card in the room, another on you, the day's cash in a pocket and the rest put away. It is also worth checking the balance every two or three days in the bank's app, because an odd charge is easier to dispute after two days than after twenty, and a security block takes five minutes to clear if you catch it early.
What people always ask
Six questions that come up before every first trip, answered with what is actually known and without promising anything that depends on your own bank. Fee conditions vary so much between institutions that the only honest answer to several of them starts with reading the card agreement before you leave, looking for two specific lines: the charge for withdrawing abroad and the percentage loading for currency conversion. With those two figures in hand you can decide which card travels in your pocket and which one stays in the room as a reserve.
One idea does not fit into a short answer. Cash in Mexico is not a nuisance to be escaped but the normal way of buying market food, paying for a shared minibus or leaving a tip, and handling it well changes how you move around the country. A tidy fold of twenties and fifties opens doors no card opens, particularly outside the big cities, and it avoids the awkward change conversation at the worst possible moment. It is a matter of habit rather than skill, and most people pick it up within the first two days.