Area Code 2421 – Oslo
The phone area code for Oslo is 2421 (international format +472421). Browse local exchange codes (NXX) and carrier assignments below.
📞 Exchange Codes (NXX) for Area Code 2421
Select a central office code to view local carrier data and detailed information
📍 Geographic Location of Oslo
Overview of Area Code 2421
Area code 2421 is a geographic National Destination Code (NDC) assigned to the Oslo metropolitan area in Norway. It is part of the country's public switched telephone network (PSTN) numbering plan, which adheres to the ITU-T E.164 recommendation. The code 2421 is used for fixed-line services, typically serving businesses and residential subscribers within the central and eastern districts of Oslo. When dialing from abroad, the full international format is +47 2421 XXX XX, where +47 is Norway's country calling code. Domestically, callers within Norway must dial the eight-digit subscriber number in the format 2421 XXX XX, omitting the trunk prefix '0' as Norway does not use a national trunk prefix for geographic numbers.
Geographic Coverage and Administrative Jurisdiction
The 2421 prefix falls under the jurisdiction of the Norwegian Communications Authority (Nkom), which oversees the allocation of numbering resources. Geographically, it covers the urban core of Oslo, including neighborhoods such as Grünerløkka, St. Hanshaugen, and parts of the city center. Oslo is the capital and most populous city of Norway, serving as the political, economic, and cultural hub. The area code is not overlay-based; each geographic NDC in Norway is unique to a specific region, and there are no overlay plans for Oslo. This means that the 2421 prefix is exclusively associated with fixed-line services in that area.
Dialing Formats and Caller Instructions
For local callers within Norway, dialing a 2421 number requires only the eight-digit number (e.g., 2421 123 45). There is no need to add any trunk prefix. For international callers, the correct format is +47 2421 123 45 (or 0047 2421 123 45 from countries using the international dialing prefix 00). When calling from a mobile phone, the plus sign (+) is typically used to denote the international access code. It is important to note that Norwegian fixed-line numbers are not portable to other geographic areas, but they can be ported to VoIP providers while retaining the original NDC, subject to Nkom regulations.
Usage and Numbering Plan Considerations
The 2421 prefix is primarily used by small and medium-sized enterprises, government offices, and residential customers. As with all geographic numbers in Norway, the tariff for calling a 2421 number depends on the caller's operator and subscription plan. Calls from mobile networks may incur higher rates than fixed-line calls. Since the implementation of number portability, subscribers can switch operators without changing their number, but the geographic significance remains for routing purposes. For businesses, having a 2421 number reinforces a local presence in Oslo, which can be beneficial for customer trust and local marketing.