You must also carry a Mexican Tourist Permit, which is issued free of charge by Mexican border officials after the proof of citizenship is accepted. The tourist permit is more important than a passport in Mexico, so guard it carefully. If you lose it, you may not be permitted to leave the country until you can replace it - a bureaucratic hassle that takes several days to a week at least. A tourist permit can be issued for up to 180 days. Those who experience any trouble in getting visa to Mexico should contact the Local Organizing Committee inmediately.
Currency exchange are available at the airport banks area, banks and exhanges houses.
Traveller checks may be also exchanged in these places. Banking hours are 9-17 hrs. Monday to Friday. Visa and Mastercard credit cards are accepted by the most of the airlines, travel agents, hotels, reaturants and shops. American Express cards are widely accepted too.