Area Code 2427 – Oslo
The phone area code for Oslo is 2427 (international format +472427). Browse local exchange codes (NXX) and carrier assignments below.
📞 Exchange Codes (NXX) for Area Code 2427
Select a central office code to view local carrier data and detailed information
📍 Geographic Location of Oslo
Geographic Coverage and Administrative Jurisdiction
The Norwegian country code +47 is followed by the geographic area code 2427, which is allocated to the Oslo metropolitan region. As a National Destination Code (NDC) within the Norwegian telephone numbering plan, 2427 designates a specific Central Office Code (COC) serving the capital city and its immediate administrative boundaries. Oslo, as the seat of the national government and a major economic hub, utilizes this prefix for fixed-line PSTN connections. The code is assigned to physical landlines within the city's telecom infrastructure, and its use is governed by the Norwegian Communications Authority (Nkom).
Dialing Formats and Caller Instructions
For local callers within Norway, the number is dialed in the national format: 24 27 xx xx. This includes the area code but omits the leading +47. For international callers, the full E.164 format must be used: +47 24 27 xx xx. When dialing from abroad, the plus sign (+) represents the international access prefix (00 in most countries), followed by the country code 47 and the complete national significant number, which includes the area code and subscriber number. It is important to note that Norwegian fixed-line numbers are not portable across geographic areas; the 2427 prefix is permanently tied to the Oslo exchange area.
Overlay Considerations and Numbering Plan
Oslo is served by multiple area codes, including 2, 3, 6, and 9, which are part of a closed numbering plan where the area code is always dialed, even for local calls. The 2427 prefix is one of many COCs within the 2x range, which is dedicated to geographic fixed-line services. There is no overlay code for Oslo; instead, the numbering capacity is managed through the allocation of additional COCs as demand grows. This ensures that the 2427 prefix remains a reliable indicator of a subscriber's geographic location within the city.
Technical and Regulatory Notes
From a technical perspective, calls to +47 2427 numbers are routed via the Norwegian PSTN, which supports both traditional copper lines and fiber-based VoIP services that are registered to a fixed address. The prefix is not used for mobile or nomadic services, and its use is strictly regulated to maintain the integrity of the geographic numbering scheme. For businesses and residents, this means that a 2427 number provides a stable, location-specific identity that is essential for local presence and emergency services routing.