Area Code 243 – Oslo
The phone area code for Oslo is 243 (international format +47243). Browse local exchange codes (NXX) and carrier assignments below.
📞 Exchange Codes (NXX) for Area Code 243
Select a central office code to view local carrier data and detailed information
📍 Geographic Location of Oslo
Geographic Coverage and Administrative Jurisdiction
The +47 243 prefix is a geographic National Destination Code (NDC) assigned to the Oslo metropolitan area, the capital and most populous city of Norway. This code falls within the 2x numbering range historically allocated to Oslo and its immediate surroundings. Specifically, numbers bearing the 243 prefix are used for fixed-line PSTN and VoIP services registered to addresses within Oslo's administrative boundaries. The coverage area includes the city center (Sentrum), major districts such as Frogner, St. Hanshaugen, Grünerløkka, and Gamle Oslo, as well as parts of the surrounding urban agglomeration. As Oslo is the political, economic, and cultural hub of Norway, this prefix is commonly associated with government institutions, corporate headquarters, financial services, and residential subscribers within the city.
Dialing Formats and Caller Instructions
For callers within Norway, the national trunk prefix '0' is not used; instead, the full national significant number (NSN) is dialed directly. The NSN for this prefix comprises eight digits, beginning with the NDC '2' followed by the subscriber number. For example, a local Oslo number might be formatted as 24 3X XX XX (with spaces for readability). When dialing from a Norwegian fixed or mobile line, one simply dials the eight-digit number: 243XXXXX. No trunk prefix is required.
For international callers, the country calling code +47 must be included. The international format is +47 243XXXXX, where the leading '0' (if any) is omitted. For instance, to call a number in Oslo with the local number 24 30 00 00, an international caller would dial +47 24 30 00 00. It is important to note that Norwegian numbers are not area-code dependent for mobile dialing; however, for fixed-line numbers, the NDC is an integral part of the number and must always be dialed, even for local calls within Oslo.
Overlay and Numbering Plan Considerations
Norway employs a closed numbering plan with no trunk prefix. The country code +47 is shared with Svalbard and Jan Mayen. There are no overlay codes in Norway; instead, geographic numbers are assigned based on the subscriber's physical location. The 243 prefix is one of several NDCs serving Oslo, including 21, 22, 23, 24, and 40 (the latter for mobile). As of recent years, there has been no plan to introduce additional digits or change the existing structure. However, with the increasing adoption of VoIP and number portability, a number with the 243 prefix may not necessarily be physically located in Oslo if the subscriber has ported the number to a provider in another region. Nevertheless, the number retains its geographic significance for regulatory and emergency services purposes.
Practical Guidance for Callers
When calling an Oslo number from abroad, always replace the local leading '0' (if any) with the international access code of your country, then dial +47 followed by the eight-digit number. For example, from the United States, you would dial 011 47 243XXXXX. From the United Kingdom, it would be 00 47 243XXXXX. Ensure that you do not add an extra '0' after the country code. For local callers, simply dial the eight-digit number. If you are unsure about the correct format, consult your service provider or the official Norwegian Communications Authority (Nkom) guidelines.