Area Code 42 – Chillán, Biobío

Geographic Coverage and Administrative Jurisdiction

The country code +56 is assigned to Chile under the ITU-T E.164 international numbering plan. Within Chile, the area code 42 is a geographic National Destination Code (NDC) that serves the city of Chillán and its surrounding areas in the Ñuble Region (Región de Ñuble). Historically, this region was part of the Biobío Region, but since 2018 it has been administratively separate. The code covers the capital city of Chillán, along with nearby communes such as Chillán Viejo, Coihueco, Pinto, and San Ignacio. This geographic code is used for fixed-line PSTN and VoIP services that are registered to physical locations within this coverage area.

Dialing Formats and Caller Instructions

When dialing a number within the Chillán area code, the national trunk prefix is 0, followed by the area code 42 and the subscriber number, which is typically 7 digits long. For example, a local landline number might be formatted as 42 2 234 567 when dialed domestically. To call this number from another region within Chile, you would dial 0 42 2 234 567. International callers should omit the trunk prefix and dial the full international format: +56 42 2 234 567.

For local calls within the same area code, it is common to dial only the subscriber number, but for clarity and to avoid issues with number portability, it is recommended to dial the full national number including the area code. There are no overlay codes currently in effect for this area, so the 42 code remains unique for this geographic region.

Numbering and Routing Considerations

Fixed-line numbers under the 42 code are allocated by the Subsecretaría de Telecomunicaciones (SUBTEL) to local incumbent operators and alternative carriers. Since the implementation of number portability in Chile, subscribers can retain their geographic number even if they change service providers, but the number's geographic significance remains tied to the original location. This means that calls to a 42 number are routed based on the original exchange, regardless of the current provider's network.

For businesses and residents in Chillán, having a local geographic number can enhance trust and local presence. When calling from abroad, it is essential to use the correct international access code (e.g., 00 from most countries) followed by 56 and the area code without the leading 0. For example, from the United States, you would dial 011 56 42 2 234 567.

As Chile continues to expand its fiber-optic and 5G networks, fixed-line numbers remain relevant for residential and business services, including high-speed internet and IP telephony. The 42 area code is an integral part of the national numbering plan, ensuring efficient call routing and connectivity for the Ñuble Region.