Following these tips will save you 15-20% when you are in Mexico. Do not exchange money at the airport money exchange. You will get a bad rate. Don't use the ATMs at the hotels. They will give you US dollars only, with the idea that you will then go to the front desk and exchange your dollars for pesos there, again, at a bad rate. Get your money at the ATMs away from the hotels. They are everywhere and you can get pesos at Wall Street rates. This will be 15-20% better than exchanging dollars for pesos no matter where you go. Don't use dollars in the restaurants. Bad rate again. Use pesos, or use your credit card. If you use your credit card, ask the restaurant to charge this through their PESO account. If they use their AMERICAN account, they will convert the bill from pesos to dollars, again at a bad rate, and then charge through their dollar account. If something is billed in dollars, like activities; wave runners, whale watching boats, fishing boats, parasailing, vendor items, etc., pay in dollars. If something is billed in pesos, like restaurants or bars, pay in pesos.