Area Code 2137 – Oslo
The phone area code for Oslo is 2137 (international format +472137). Browse local exchange codes (NXX) and carrier assignments below.
📞 Exchange Codes (NXX) for Area Code 2137
Select a central office code to view local carrier data and detailed information
📍 Geographic Location of Oslo
Overview of Area Code 2137
Area code 2137 is a geographic prefix within the Oslo numbering plan of Norway, assigned under the national destination code (NDC) 21. The code 21 is one of several geographic area codes serving the capital city and its surrounding metropolitan region. Specifically, numbers formatted as +47 21 37 XX XX are allocated to fixed-line subscribers and businesses located in Oslo, the administrative and economic heart of Norway.
Coverage and Administration
The 2137 prefix falls under the jurisdiction of the Norwegian Communications Authority (Nkom), which oversees the national E.164 numbering plan. Oslo's geographic numbering is subdivided into multiple NDCs, including 21, 22, 23, 24, and others, to accommodate the high density of telephone lines in the capital. The 2137 block is typically used by enterprises, government offices, and residential customers within the city limits. It is not assigned to a specific district but is part of the broader Oslo exchange area, meaning that a number with this prefix can be located anywhere within the municipality.
Dialing Formats
For local callers within Norway, the number is dialed as 21 37 XX XX (without the country code). For international callers, the full international format must be used: +47 21 37 XX XX or 0047 21 37 XX XX from countries using the international prefix 00. When dialing from a mobile phone, the plus sign (+) is recommended for international calls. It is important to note that Oslo's geographic numbers are not portable to other regions, but they can be ported between operators within the same geographic area.
Caller Instructions
- Local callers (within Norway): Dial the 8-digit subscriber number directly, e.g., 21 37 12 34.
- International callers: Dial your country's exit code (e.g., 011 from the US, 00 from most European countries), followed by 47, then the 8-digit number: 21 37 12 34.
- VoIP and mobile users: Always use the +47 prefix when storing numbers in international format to ensure proper routing.
Overlay and Numbering Considerations
Oslo does not currently have an overlay code; each NDC covers distinct number ranges. However, due to the growth of VoIP and mobile services, geographic numbers like those in the 2137 range can be used for fixed-line services, and some operators may route them over IP networks. Callers should be aware that charges for calling a 2137 number depend on the caller's operator and tariff plan, but they are treated as standard national geographic calls.