A law that took effect in January 2026 requires every mobile phone number in Mexico to be registered with the government under a verified identity. The original compliance deadline of 30 June 2026 passed with fewer than half of all lines registered, and authorities have now announced an extended timetable focused on pre-paid (prepago) customers.
For travellers, the change has a direct practical effect: if you buy a local SIM card in Mexico, you now need to present a valid passport at the point of sale so the vendor can register the number in your name. Major carriers - Telcel, AT&T México, and Movistar - have updated their point-of-sale processes to capture this data.
What to expect when buying a SIM
At most airport kiosks and phone shops you will hand over your passport, the vendor enters your details into the carrier’s registration system, and the SIM is activated in your name. The process adds a few minutes to what was previously a quick transaction but is otherwise straightforward at compliant retailers.
Pre-paid SIM cards that remain unregistered after the extended deadline risk having service suspended until registration is completed. Cards sold before the law took effect are not exempt.
Better options for avoiding the registration process
eSIM: If your phone supports eSIM - most handsets released after 2022 do - Mexico eSIM plans can be activated remotely before you travel. No in-country registration, no queue at a kiosk.
International add-on from your home carrier: For stays of a week or less, roaming add-ons from carriers in the US, UK, and EU have become more competitive in price. Worth comparing against the cost of a local SIM if registration feels like friction.
Buy at a certified airport retailer: Airport Telcel and AT&T kiosks are the most likely to have compliant registration procedures in place and staff who have handled foreign passport holders before.
Coverage notes
Mexico City and Cancún have comprehensive 4G and 5G coverage across urban and resort areas. Rural inland areas - the Sierra Madre, parts of Chiapas, and remote sections of the Yucatán Peninsula - remain patchy regardless of carrier. Telcel has the broadest national coverage, including in areas where AT&T and Movistar have limited signal.
For a full introduction to planning your first trip, including getting a local number and connectivity tips, see our first-time Mexico guide.