Before you start

An unlocked, band-compatible handset
Passport, or resident card once issued
A CURP — definitive for residents, temporary from RENAPO for everyone else
A Mexican bank card or account for a postpaid plan

Step-by-step

1
Buy prepaid at any OXXO on day one
Telcel Amigo has the broadest national coverage. AT&T is genuinely competitive in the north-east, having built on the old Iusacell and Nextel networks. Bait, on Altan, is cheapest and thinnest. SIMs are sold at OXXO, Walmart, carrier stores and the airport.
In personWho: YouUnder 30 minutesMXN 50–150
2
Register the line to your CURP and photo ID
Link the number through the carrier's portal or app using your CURP and a passport, INE or resident card. It is free and takes minutes, and an individual may hold up to ten lines under one CURP. Unregistered prepaid lines began being suspended on 15 August 2026 on a rolling calendar by last digit, and a dead SIM cannot receive your bank's verification codes. Postpaid contracts were registered when you signed them.
OnlineWho: Every prepaid line holderSame dayFree
3
Pick the plan for the border if you cross regularly
AT&T México plans and Telcel's larger Amigo bundles include calls, texts and data in the United States and Canada. If you drive to McAllen or San Antonio monthly, or take calls from a US employer, this removes roaming charges entirely and is the reason many regios stay on one carrier rather than the cheapest one.
OnlineWho: Anyone crossing the borderBundles from around MXN 200 for 30 days
4
Keep the prepaid number alive
Packages expire, typically after 30 days, and unused numbers can eventually be recycled. Dial *133# on Telcel to check balance, data and expiry without using data. Losing a number that receives banking codes is a slow, avoidable mess.
Mobile appWho: You
5
Switch to postpaid once you have a Mexican salary
Postpaid costs less per gigabyte but requires a credit check, an address and a local payment method. Most newcomers qualify after a few months. Portability lets you keep the number; never cancel the old contract before the transfer completes.
OnlineWho: You≈MXN 200–600 a month
6
Order fibre and plan for summer power cuts
Totalplay, Izzi and Telmex all cover the metro area with cheap symmetric fibre. What to plan for is the grid: peak air-conditioning demand and summer storms produce outages. A UPS on the router and a phone plan with real hotspot data is the difference between a lost afternoon and an inconvenience.
OnlineWho: Remote workersOne to three weeks to install

Documents you’ll need

Passport or resident card
CURP, definitive or temporary
Mexican bank card or account for postpaid billing
Proof of address for fixed-line installation

Things most newcomers don’t know

The registry that returned in 2026 is CURP-based, and it will cut your line if you ignore it.

The Supreme Court struck down PANAUT, which would have collected biometrics, and many arrivals still believe Mexican prepaid is anonymous. Linking a line to a CURP became compulsory on 9 January 2026, and suspension of unregistered prepaid numbers runs from 15 August to 31 December 2026 on a calendar keyed to the last digit of the number. No fingerprints are taken — but a suspended SIM stops receiving two-factor codes, which is worse than it sounds.

Source: CRT — registro de líneas móviles

In Monterrey the right plan is the one that works in Texas, not the cheapest one.

AT&T México and Telcel's larger bundles include usage in the United States and Canada at no extra cost. In a city two and a half hours from Laredo, where supplier visits, flights out of San Antonio and family across the border are ordinary, that inclusion is used constantly. Choosing a budget MVNO to save a hundred pesos and then paying roaming on every crossing is a false economy people make once.

Source: carrier plan terms

A temporary CURP is enough to register a line, so tourists are not locked out.

People arriving before their residency is finalised assume the registration rule prevents them from holding a Mexican number at all. RENAPO issues a temporary CURP against a passport, free and online, and carriers accept it. It takes five minutes and saves either roaming charges or weeks on a travel eSIM while the INM process runs.

Source: RENAPO / gob.mx

Summer grid stress, not the network, is what takes remote workers offline here.

Monterrey's electricity demand peaks hard in July and August when every air conditioner in the metro area runs at once, and summer storms bring their own outages. Fibre keeps working; your router does not, because it has no power. A small UPS on the router and modem, plus a phone plan with generous tethering, converts a four-hour outage into a minor annoyance.

Source: community-reported

Common mistakes to avoid

Never registering the line and losing the number along with your banking codes.
Buying the cheapest MVNO and then paying roaming on every trip to Texas.
Assuming a tourist cannot get a Mexican number — a free temporary CURP solves it.
Letting prepaid credit lapse until the number is recycled.
Working from home in August with no UPS on the router.

Some of this may be out of date. Spotted something inaccurate? Help us keep it right for the next newcomer.