The official money in Mexico is the Mexican Peso. Cancun is a tourist resort therefore money from other countries are also accepted in most of the places. US dollars are accepted almost everywhere in Cancun. Currencies from other countries can be easily exchange at Money Exchange Houses located all over town, at banks or at your hotel. Banks will give you the highest exchange rate but the difference is only a few Mexican cents. It is highly recommended that you exchange your money at your hotel, it is easy and most convenient.

You don't have to exchange all of your money into pesos. Just exchange a few pesos to get you by the first day and remember that every time that you pay with US dollars you will get change in pesos, therefore, you will end up with a lot of pesos at the end of your vacation.

Being a Mexican peso expert is not going to make you rich but knowing the exchange rate of the day can save you some money. You can check the exchange rate at your hotel every day and you can get a "exchange rate cheat sheet" at money exchange houses or at the concierge of your hotel.