Airports often give the worst exchange rates, but I don't really remember or didn't notice what it was like there.

Don't you have an ATM card? I often just use an ATM in Mexico, although I noticed when in Playa del Carmen over Thanksgiving, that the main pedestrian street with all the tourist traffic only has private ATMs. Wonder how they worked out that deal with the banks, but I had a map showing banks, so just walked a block north and used a real bank ATM. There was a real bank near the ferry, also. IN any case, I don't really know what kind of fees the private ATMs charge, or the laws in Mexico regarding notices of the fees before you finish the transaction. Maybe someone else knows those. If it's only a couple dollars fee, and the exchange rate is your bank, as usual with a bank ATM, it might be a better idea than the airport anyway.

Of course local buses want pesos, they are Mexican. As for small businesses, never saw that, all of the ones I've seen recently, large or small, will take USD or pesos (in Cancun or Playa del Carmen, only places I noticed). You do have to check the rates they are giving, a lot of them were very fair and gave about the bank rate (13 pesos to $1). But one restaurant changed at 10 pesos to $1, a real bad deal, and some stores gave more like 12. The exchange booths (people-manned) were almost all giving 12.35 to $1 when I was in PDC recently and the official rate was 13. So that's a 5 pct markup.

In any case, there are many options, you just have to know the rates and the math and decide what works for you. But the idea that you'd need to get it in the US or the airport is wrong. There are many other ways to get pesos. I don't know where you are in Cancun, but there will probably be many ATMs and exchange booths around it, there are in the main hotel zone.

oh, and believe me, no one is going to object to you tipping them in USD in Cancun.

Always use pesos in Mexico and you will get the best exchange. An ATM is the easiest and best way to go. Although banks charge different rates for forieghn exhcnag fees. Take out more, pay less fees. You can get a good rate changing cash at banks but the wait is often prohibitive. Check rates at Casas de Cambios and you can usually get a good deal. Often a couple of blocks away from main tourist areas will get you a better excahnge.

ATMs, stick to bank associated ones. There are some at the airport. I usually have pesos left over from my last trip to get me started.

If you use dollars you will pay 30% more for everything. As above said. Use your ATM card at any bank in Mexico for the best exchange rate.

We just came from Cozumel and we were told to make sure you use an ATM at a bank, not a free-standing machine that is not part of a bank. They told us the ATM fee could be as much as $25 if you don't use a bank ATM.

Great replies...thanks so much. Now I wonder if we can find a bank-related ATM in the airport becuase we have transfers through the tour operator directly from the airport to the hotel and I'm sure they don't stop at banks along the way. I just want to have pesos in hand by the time we reach the hotel so if we want to tip for good service, housekeeping, a particular bartender we're set as soon as we arrive!

<I just want to have pesos in hand by the time we reach the hotel>

I usually order $200-worth from my home bank, and get them in as assortment of smaller bills. You get a bit less of an exchange rate but it is convenient.

Or use your debit card at an ATM upon arrival (as a BoA customer I can use either Santander or Scotia without fees).

Or take USD cash and exchange it at a "casa de cambio" (change house) or even your hotel front desk (again not the best rate but convenient).

Don't use the exchange booths at airports, they are pretty much universally a rip-off. ATMs are OK, doesn't matter their location the rate is the same.

Whenever I arrive in another country, I immediately visit a bank-affiliated ATM at the airport to get local currency. I do carry US$200-300 with me as a backup in case for some reason my card won't work in the ATM - then I can exchange my USD for local currency and have money to use until I get the ATM card issue sorted out.