To keep your Mexico line active, link it to your CURP by late June 2026 for existing lines. Telcel says June 29; AT&T says June 26.
Beginning in January 2026, Mexico’s mobile carriers must associate every active mobile line with an identified end user. In plain terms, your phone number has to be linked to a real person or a legal entity. The system is meant to reduce anonymous use of mobile lines for fraud and other crimes by making it harder to hide behind “unregistered” SIM cards.
For most expats, the practical takeaway is simple. If you have a Mexican number you rely on for banking codes, deliveries, work, WhatsApp, or two-factor logins, you should treat this as mandatory. It applies to both contract plans and prepaid lines. It also applies even if you rarely use voice calls. Your number is still a mobile line, and it still needs an identified owner.
The deadline that matters for existing lines
If you already have a working Mexican line before the process begins, you are not expected to do it all on day one. But you do have a hard cutoff in late June 2026. After that, your service can be suspended until you complete the linking.
The rule is built around a “grace window” measured in business days after the carriers’ registration platforms are in place. That window lands in late June 2026 for most users, which is why you’ll see carriers setting deadlines around that period. If you miss the cutoff, your number is not automatically “lost,” but it becomes effectively unusable for everyday communication until it is linked.
Telcel and AT&T dates you should follow
Carriers are publishing their own timelines so customers know exactly where they stand.
Telcel says it will begin the process in early January 2026. If you already have a Telcel line, the published deadline is June 29, 2026. After that date, Telcel says lines that are not linked will be suspended until the registration is completed.
AT&T is taking a two-track approach. For any new AT&T line activated on or after January 7, 2026, the line must be linked to have service. For existing lines activated before that date, AT&T says you must complete the linking no later than June 26, 2026. If you miss the deadline, the line will remain without service until you finish the process.
If you’re not with Telcel or AT&T, don’t assume you’re exempt. The requirement applies across providers, including smaller carriers and virtual operators. The dates may differ slightly, but the logic stays the same: link it within the window or accept a service suspension.
What happens if you do nothing
This is not a small inconvenience. Once a line is suspended for not being associated with an identified user, you should expect your phone to stop functioning for everyday communication. No normal calls. No normal SMS. That includes many of the “hidden” SMS messages you depend on, like login codes, bank verifications, delivery confirmations, and account recovery texts.
During suspension, the line is limited to emergency and citizen-service calls only, including 074, 079, 088, 089 and 911. For most people, that means the phone becomes a safety device, not a working line.
The good news is that suspension is reversible. Once you complete the linking, the line can be re-enabled. But that doesn’t undo the damage of being unreachable for days or weeks, or losing access to accounts that depend on that number.
What expats should do now so summer 2026 is painless
Don’t wait until June. Late June is when thousands of people will suddenly realize their number is on the line, and carrier support queues will spike.
If you are a resident in Mexico, you likely already have a CURP tied to your immigration status. Have it handy, along with your current ID, and make sure your name matches what the carrier has on file. If you changed passports, updated your residency card, or registered your line years ago with a different spelling, fix that now rather than under a deadline.
If you are in Mexico on a tourist stay but still keep a Mexican SIM, pay attention to what your provider accepts for identification. In practice, many foreigners will link using a passport. Either way, the point is the same: your line must be connected to a verifiable identity in the carrier’s system.
You can complete the process in person at carrier service centers or remotely through the registration platform your provider will publish for customers. If your Mexican number matters to your daily life, set a calendar reminder for January, then knock it out early. Five minutes in February is better than a dead phone in late June.
