Area Code 230 – Oslo
The phone area code for Oslo is 230 (international format +47230). Browse local exchange codes (NXX) and carrier assignments below.
📞 Exchange Codes (NXX) for Area Code 230
Select a central office code to view local carrier data and detailed information
📍 Geographic Location of Oslo
Geographic Coverage and Administrative Jurisdiction
The +47 230 prefix is a geographic National Destination Code (NDC) assigned to the central business district of Oslo, Norway's capital and largest city. This code falls within the broader Oslo numbering area, which encompasses the city's administrative boundaries and select adjacent municipalities. As a geographic allocation, numbers bearing the 230 prefix are tied to physical infrastructure within this region, although modern PSTN and VoIP services may route calls to any location via number portability.
Dialing Formats and Caller Instructions
For domestic callers within Norway, the number is dialed in its national format: 230 XX XXX (eight digits total, including the leading '2'). No trunk prefix '0' is used, as Norway employs a closed numbering plan with no national significant number (NSN) prefix. International callers must replace the leading '2' with Norway's country code, resulting in the format +47 230 XX XXX. When dialing from abroad, omit any leading zeros—there are none in this case—and ensure the plus sign or the international access code (e.g., 00 from most European countries) precedes the country code.
Primary Services and Numbering Considerations
The 230 prefix is predominantly used by businesses and organizations requiring a local Oslo presence. It supports both traditional PSTN lines and VoIP-based services, allowing enterprises to establish virtual offices in the capital. Overlay codes are not applicable here, as 230 is a distinct NDC within the Oslo area; however, number portability means a subscriber may retain their 230 number even if they relocate outside the geographic region, subject to regulatory guidelines.
For callers, charges vary depending on their telecom provider and subscription plan. Calls from mobile phones may incur higher rates than fixed-line calls, and international rates apply when dialing from abroad. It is advisable to check with your operator for specific tariffs.
In summary, +47 230 is a geographic code serving Oslo's central area, essential for businesses aiming to establish a local footprint. Whether you are a domestic caller or an international client, understanding the correct dialing format ensures seamless connectivity.