Mexico's mobile-line registration, from the December 2025 rules to the 2026 deadlines: what visitors need

On Monday, December 8, 2025, Mexico's telecommunications regulator, the Comisión Reguladora de Telecomunicaciones (CRT), approved guidelines that tie every mobile phone line in the country to an identified person or company. The Diario Oficial de la Federación published them on December 9, and they took effect that day. Since January 9, 2026, according to the CRT, every mobile line must be associated with a person or a company, and that includes the SIM or eSIM a visitor buys in Mexico.

What the guidelines require

Before the rules, Mexico was one of the few countries where a SIM could be bought without identification, the CRT said; operators already registered their postpaid customers. The guidelines bind every company that provides mobile phone service. Any SIM, physical or electronic (eSIM), sold through any channel can, until it is linked, only receive emergency alerts and call the emergency and citizen-service numbers (074, 079, 088, 089 and 911) and the provider's customer service. Linking turns on the services paid for. SIMs that cannot make voice calls, send SMS or make internet calls are exempt.

Providers may not charge for linking, unlinking or checking which lines are in a person's name, and must give free access to their linking platforms, whatever the plan or the balance on the line. A person may link up to ten lines.

What a foreign visitor needs

For Mexicans, the guidelines accept three official IDs that carry the CURP, the population registry code: the voter card, the Mexican passport and the national identity document. For foreign nationals, article 20 requires a passport or a temporary CURP for foreigners. The provider then records only the name, country of origin, passport number or temporary CURP, the phone number and the result of the identity check.

Linking can be done in person at the provider's service center or, if the customer prefers, remotely on the provider's platform. The remote route asks for an image of the ID and a "prueba de vida," a live check that the person matches it, validates the CURP with the national population registry and allows three attempts. Once a line is linked, the provider issues a folio with the date and time.

From a June 30 deadline to a calendar by last digit

The guidelines gave providers 30 days to set up their linking platforms and, 120 business days after that, required them to disable every line not linked to a person. In April 2026 the CRT launched a national campaign, "Registra tu línea," with June 30 as the end of that period. On June 25 it announced that prepaid lines still not linked would get deadlines by the last digit of the number, between August and December. By then 63 million lines were linked: 40.2 million prepaid and 22.8 million postpaid, which needed no new step because they were tied to a person when contracted.

On August 13, two days before the first deadline, the CRT said there would be no extension. Once a digit's deadline passes, providers suspend unlinked lines within 72 hours. A suspended line keeps its number: it can still call 911, 079, 088 and 089 and its provider, and receive earthquake alerts, and service returns as soon as the line is linked. Anyone can link before their digit's date.

Where it stands

By October 18, 2026, 96,347,821 lines had been linked, 80.3% of those the CRT expects, it said the next day. It expects about 25 million lines that are no longer used to be purged, among them gift SIMs that were never activated and single-use SIMs bought by temporary visitors. The CRT's calendar gives lines ending in 5 until October 31, and those ending in 6, 7, 8 and 9 until November 15 and 30 and December 15 and 31.

Roaming and foreign eSIMs

The guidelines left one question for later. Their ninth transitory article says that once the 2026 FIFA World Cup is over, the CRT will define how lines that use international roaming in Mexico are to be linked. By October 31, 2026, none of the CRT's press releases had announced those mechanisms.

The CRT has since spoken about foreign eSIMs. On September 14 and October 6, 2026, it said many foreign data eSIMs cannot receive the calls or SMS codes needed for banking and app verification; that wholesale agreements between operators and international fair-use policies prohibit permanent roaming, so a foreign eSIM is not necessarily a lasting alternative to a Mexican line; that such eSIMs can cost up to 10 times more per gigabyte than Mexican rates; and that any eSIM supplied by companies operating in Mexico falls under exactly the same linking rules.

Before you travel

• If you plan to buy a Mexican SIM or eSIM, take your passport: until the line is linked, it can only call emergency numbers and the provider.
• Linking is free. The CRT says the links to every company's platform are on its portal, registratulinea.crt.gob.mx.
• For questions, the CRT points to dudasvinculacion@crt.gob.mx and the government's 079 line, which it says runs 24 hours a day.