Toll free numbers in Mexico are only free within Mexico itself. International long distance charges apply when dialing a Mexican toll free number from the United States. There's no guarantee that the person answering the call will speak English. Most Mexican businesses that cater to people from the States offer toll free U.S. numbers with English speaking operators or other alternatives for contact.
Dial 011-52 plus the 800 number. The country code for Mexico is 52, and 011 is the calling code to dial anywhere outside of the U.S. The call may or may not go through. International long distance charges apply. You can also ask an international operator from your phone company to place the call, for an additional charge.
Purchase a pre-paid phone card. Gas stations, stationery stores, grocery stores, drugstores and supermarkets in the U.S. often sell pre-paid phone cards for calling Mexico. A $10 phone card gives approximately two hours of airtime. Activate the phone card and dial the toll free number using the 011-52 system. Time is deducted with each call, and there's no guarantee of a successful connection.
Check with the Mexican company or business to see if it has either a U.S. phone number or a local Mexican phone number. Dial 011-52 plus the local phone number. Airlines, hotels, major business and companies in Mexico generally have at least a local number or a U.S. number.