To call "toll free" telephone numbers in the US and Canada from México, use the following conversions:

INSTEAD OF                                                                   DIAL                  

  1-800-XXX-XXXX                                                            001-880-XXX-XXXX

  1-866-XXX-XXXX                                                            001-883-XXX-XXXX

  1-877-XXX-XXXX                                                            001-882-XXX-XXXX

  1-888-XXX-XXXX                                                            001-881-XXX-XXXX

Note:  Most US and Canadian "toll free" numbers are not toll free if dialed from outside their respective country.  You will usually be charged at international direct dial rates when you makes these calls.