Port of Entry at San Ysidro, which is about 20 minutes from the San Diego airport (functional 24*7)
Travel Documents Required
Passport/Visa: US and Canadian citizens do not require a visa; however, they need to have a valid passport to enter Mexico (passport card for Tijuana).
Permit for Travel Beyond Border Zone: Obtaining a Forma Migratoria Multiple (FMM) which is available at Mexican consulates and border entry points for travel beyond the border zone (25 km from the US border) and a stay exceeding 72 hours is compulsory.
Entering By Air: Obtaining an FMM is mandatory; the fee is usually included in the plane ticket price. The FMM can be obtained from:
Mexican consulates, Border crossings, Mexican tourism offices, Airports within 20 to 30 kilometers from the border, Majority of the airlines connecting to Mexico
As the FMM needs to be returned to authorities on leaving the country, it should be preserved carefully; failure to return it may carry penalty, detention, deportation, or denied entry into Mexico in the future.
*SAN – San Diego International Airport: Suggested American airport near Tijuana for free pick-up, Airport to Tijuana: 20 Mins