Historically and commonly associated with Mexico City. This guide separates the geographic area code from country calling code +52 and explains how to write both domestic and international formats.
Prefix 55 is a historical and common city association, not proof of a number’s current location under Mexico’s post-July-2025 zone model.
This schematic shows the published numbering association without inventing precise geographic boundaries.
Historically and commonly associated with Mexico City
Area code 55 is published for Historically and commonly associated with Mexico City in Mexico. Prefix 55 is a historical and common city association, not proof of a number’s current location under Mexico’s post-July-2025 zone model.
It should be interpreted as a numbering-plan association, not a live geolocation result.
Multiple IANA time zones; rules vary by location
America/Mexico_City: Calculated in your browser
America/Cancun: Calculated in your browser
America/Tijuana: Calculated in your browser
America/Hermosillo: Calculated in your browser
Where a code spans several zones, confirm the destination city before calling.
Uniform ten-digit dialing began on 3 August 2019 and became the sole national format on 3 August 2020, removing 01, 044, 045 and the extra international mobile digit 1. Since 1 July 2025, numbering resources have been administered through eight broad zones.
Every city association on this site is described as historical or common, not exclusive. Providers can use numbering resources elsewhere within the applicable zone, and a number can move through portability or service changes.
“Nearby” means related entries in this country directory, not a guarantee of a shared physical border.
Historically and commonly associated with Guadalajara
MexicoHistorically and commonly associated with Monterrey
MexicoHistorically and commonly associated with Puebla
MexicoHistorically and commonly associated with Tijuana
MexicoHistorically and commonly associated with León
MexicoHistorically and commonly associated with Ciudad Juárez
Administrative units and telephone zones are different entity types; the list reflects featured city associations only.
The directory includes up to 50 verified or clearly qualified city associations and does not claim exhaustive coverage.
Current operator and market-share data are dynamic. This page avoids assigning a specific number to a carrier from its area code alone.
Area code 55 is a geographic fixed-line identifier. Consult Comisión Reguladora de Telecomunicaciones (CRT) for live allocation or licensing information.
Wireless numbers commonly use separate non-geographic ranges. Number portability prevents reliable current-carrier identification from a prefix alone.
Domestic code: 55
International prefix: +52 55
A number beginning +52 55 matches this geographic pattern. Keep the remaining subscriber digits intact. This directory does not perform reverse lookup or identify a private subscriber.
55 is associated with Historically and commonly associated with Mexico City in Mexico. Prefix 55 is a historical and common city association, not proof of a number’s current location under Mexico’s post-July-2025 zone model.
Use +52 55 followed by the subscriber number; remove any domestic trunk prefix.
No. It describes numbering-plan association, while portability, forwarding and internet calling can separate a number from the caller’s current location.