If you're planning to travel to Mexico with children, either your own or someone else's, it is vital to ensure that you have the correct documentation. Besides a passport and possibly a travel visa, it may be required to prove that both of the child's parents or the child's legal guardian has given their permission for the child to travel. If the immigration officials are not satisfied with the child's documentation, they may turn you back, which can create a major hassle and even derail your travel plans completely.
Many countries require children traveling without their parents to present documentation that proves that the parents gave their authorization for the child to travel. This measure is to help prevent international child abductions. In the past, it was an official requirement of the Mexican government that any child entering or exiting the country carry a letter of permission from their parents, or from the absent parent in the case of a child traveling with only one parent. In many cases, the documentation was not asked for, but it could be requested by immigration officials.
Since January 2014, new regulations for children traveling to Mexico stipulate that foreign children who travel to Mexico as tourists or visitors for up to 180 days only need to present a valid passport, and are not required to present other documentation. However, Mexican children, including those holding dual citizenship with another country, or foreign children residing in Mexico who travel unaccompanied by either parent are required to show proof of their parents' permission to travel. They must carry a letter from the parents authorizing travel into Mexico.
The letter must be translated into Spanish and legalized by the Mexican embassy or consulate in the country where the document was issued. A letter is not required in the case of a child traveling with only one parent.
Note that these are the requirements of the Mexican immigration authorities. Travelers must also meet the requirements of their home country (and any other country they travel through en route) for exit and return.
Here is an example of a letter of authorization for travel:
I (parent's name), authorize my child/children, (child/children’s name) to travel to (destination) on (date of travel) aboard Airline/Flight # (flight information) with (accompanying adults), returning on (date of return).
Signed by parent or parents
Signature/Seal of Mexican embassy or consulate
The same letter in Spanish would read:
Yo (parent's name), autorizo a mi hijo/a (child's name) a viajar a (destination) el (date of travel) en la aerolinea (flight information) con (name of accompanying adult), regresando el (date of return).
Firmado por los padres
(Signature / Seal of Mexican embassy) Sello de la embajada mexicana
You can copy and paste this wording, fill out the appropriate details, sign the letter and have it notarized so that your child can carry it along with his or her passport during their travels.
Although it may not be required in all cases, carrying a permission letter from the parents can help ease travel hassles and avoid delays in case immigration authorities question a child's permission to travel, so whenever possible, it's a good idea to get one for a child traveling without his or her parents.