Area Code 644 – Sonora
The phone area code for Sonora is 644 (international format +52644). Browse local exchange codes (NXX) and carrier assignments below.
📞 Exchange Codes (NXX) for Area Code 644
Select a central office code to view local carrier data and detailed information
📍 Geographic Location of Sonora
Overview of Area Code 644
Area code 644 is a geographic numbering plan area (NPA) assigned to the state of Sonora, Mexico, under the national numbering plan administered by the Instituto Federal de Telecomunicaciones (IFT). It serves the southern and central regions of Sonora, with the primary city being Ciudad Obregón, the second-largest municipality in the state. The coverage area includes the municipalities of Cajeme, Guaymas, Empalme, and Navojoa, as well as surrounding rural communities. This code is part of the North American Numbering Plan (NANP) but operates under Mexico's country code +52, meaning calls from the United States and Canada require the full international format.
Dialing Formats and Call Routing
For local calls within the 644 area code, users must dial the 10-digit national number: the three-digit area code followed by a seven-digit local number. For example, a local call to a business in Ciudad Obregón would be dialed as 644 123 4567. When calling from a mobile phone within Mexico, the same 10-digit format applies, without the need for an additional long-distance prefix. For international callers, the format is +52 644 123 4567, where +52 is Mexico's country calling code. It is important to note that Mexico eliminated the national long-distance prefix '01' for fixed-line calls in 2019, simplifying dialing to the 10-digit format nationwide.
Geographic Coverage and Administrative Significance
Ciudad Obregón, the economic hub of the region, is known for its agricultural production and food processing industries. The area code also covers the port city of Guaymas, a key commercial and fishing center, and Empalme, which hosts a major railway maintenance facility. Navojoa, located in the Mayo Valley, is another significant city within this code. The region is characterized by a mix of urban and rural populations, with telecommunications services provided by major carriers such as Telmex, Telcel, AT&T Mexico, and Movistar. The IFT has not announced any overlay plans for 644, meaning the code remains the sole area code for this geographic region.
Practical Guidance for Callers
For callers within Mexico, simply dial the 10-digit number (area code + local number) from any fixed or mobile line. For international callers, always include the +52 country code and drop any leading '0' or '1' that may appear in local directories. For example, a number listed as 01 644 123 4567 should be dialed as +52 644 123 4567 from abroad. When calling from a mobile phone in Mexico, the same 10-digit number is used, and there is no need to add a '1' as was previously required for calls to mobile numbers. This streamlined approach ensures seamless connectivity for both domestic and international calls.