this is the official word I got emailed back to me from "The Man"
The Government of Mexico requires that all U.S. citizens present proof of citizenship and photo identification for entry into Mexico. While U.S. citizenship documents such as a certified copy of a U.S. birth certificate, a Naturalization Certificate, a Consular Report of Birth Abroad, or a Certificate of Citizenship are acceptable, the U.S. Embassy recommends traveling with a valid U.S. passport to avoid delays or misunderstandings. U.S. citizens have encountered difficulty boarding onward flights in Mexico without a passport. U.S. citizens boarding flights to Mexico should be prepared to present one of these documents as proof of U.S. citizenship, along with photo identification. Driver's permits, voter registration cards, affidavits and similar documents are not sufficient to prove citizenship for readmission into the United States.
U.S. citizens do not require a visa or a tourist card for tourist stays of 72 hours or less within "the border zone," defined as an area between 20 to 30 kilometers of the border with the U.S., depending on the location. U.S. citizens traveling as tourists beyond the border zone or entering Mexico by air must pay a fee to obtain a tourist card, also known as an FM-T, available from Mexican consulates, Mexican border crossing points, Mexican tourism offices, airports within the border zone and most airlines serving Mexico. The fee for the tourist card is generally included in the price of a plane ticket for travelers arriving by air.
Tourists wishing to travel beyond the border zone with their car must obtain a temporary import permit or risk having their car confiscated by Mexican customs officials. To acquire a permit, one must submit evidence of citizenship, title for the car, a car registration certificate, a driver's license, and a processing fee to either a Banjercito branch located at a Mexican Customs office at the port of entry, or at the Mexican Consulate in Austin, Chicago, Dallas, Houston, Los Angeles, Sacramento, San Bernardino, or San Francisco. Mexican law also requires the posting of a bond at a Banjercito office to guarantee the departure of the car from Mexico within a time period determined at the time of the application. For this purpose, American Express, Visa or MasterCard credit card holders will be asked to provide credit card information; others will need to make a cash deposit of between $200 and $400, depending on the age of the car. In order to recover this bond or avoid credit card charges, travelers must go to any Mexican Customs office immediately prior to departing Mexico. Disregard any advice, official or unofficial, that vehicle permits can be obtained at checkpoints in the interior of Mexico. Avoid individuals outside vehicle permit offices offering to obtain the permits without waiting in line. If the proper permit cannot be obtained at the Banjercito branch at the port of entry, do not proceed to the interior where travelers may be incarcerated, fined and/or have their vehicle seized at immigration/customs checkpoints. For further information, contact Mexican Customs offices about appropriate vehicle permits.
Upon arrival in Mexico, business travelers must complete and submit a form (Form FM-N 30 days) authorizing the conduct of business, but not employment, for a 30-day period. Travelers entering Mexico for purposes other than tourism or business or for stays of longer than 180 days require a visa and must carry a valid U.S. passport. U.S. citizens planning to work or live in Mexico should apply for the appropriate Mexican visa at the Mexican Embassy in Washington, DC or nearest Mexican consulate in the United States.
Mexican law requires that any child under the age of 18, of any nationality, traveling into or out of Mexico must carry notarized written permission from any parent not traveling with the child. There have been cases where children, even American children, not carrying this document have been denied entry into Mexico, or have not been allowed to board a plane in the U.S. bound for Mexico. This permission must include the the name of the parent, the name of the child, the name of anyone traveling with the child, and the notarized signature(s) of the absent parent(s). The child must be carrying the original letter - not a faxed or scanned copy - as well as proof of the parent/child relationship (usually a birth certificate) - and an original custody decree, if applicable.
For further information concerning entry and visa requirements, travelers may contact the Embassy of Mexico at 1911 Pennsylvania Avenue N.W., Washington, D.C. 20006, telephone (202) 736-1000, Internet site:
http://portal.sre.gob.mx/usa/, or any Mexican consulate in the United States.
If you have further questions, please email us at
NPIC@state.gov. Please include all prior messages or correspondence in your reply so that we may know what has taken place previously. If you prefer, you can call us at 1(877)487-2778, for TDD/TTY callers 1-888 874-7793. Our contact center is open Monday through Friday 8:00 AM-8:00 PM EST.
Thank you.
National Passport Information Center 035