You will receive this form on the plane along with the Mexican Tourist Card. One of these forms should be completed per family. (not per person)
After you go through immigration you will collect your luggage and get in line to go through customs, when it is your turn, hand this for to the officer. You will be asked to press a button that will either say to go on through or to stop for a brief search of your luggage.
This is an EXAMPLE ONLY. You must complete an original form you will receive on the plane before you arrive in Mexico.
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Click HERE for pdf to print