Area Code 2190 – Oslo

Overview of Area Code 2190

Area code 2190 is a geographic prefix assigned to the capital city of Norway, Oslo, within the national numbering plan administered by the Norwegian Communications Authority (Nkom). As part of the +47 country code, this prefix follows the ITU-T E.164 international standard. In Norway, geographic area codes are not separated by a trunk prefix (such as '0' used in many other countries); instead, the full national significant number (NSN) is dialed directly, both for domestic and international calls.

Dialing Format and Usage

When calling a subscriber with the 2190 prefix from within Norway, you dial the eight-digit number in its entirety, for example: 21 90 XX XX. From abroad, you dial the international access code (00 or +), followed by the country code 47, and then the eight-digit subscriber number: +47 21 90 XX XX. There is no need to drop any leading zero, as Norwegian numbers do not include one. The prefix 2190 is part of the 21 geographic range, which is exclusively allocated to the Oslo area. This range is used for both fixed-line and VoIP services, but it is not assigned to mobile networks, which use distinct prefixes such as 4, 9, and some 5 numbers.

Geographic Coverage and Administrative Jurisdiction

Oslo, the capital and most populous city of Norway, serves as the administrative and economic hub of the country. The 2190 prefix covers the central and surrounding districts of Oslo, including major business districts, government buildings, and residential areas. Because Oslo is a compact city, the same prefix may serve multiple neighborhoods, and there is no further geographic segmentation within the 21 range. For callers, the prefix does not indicate a specific street or district but confirms that the line is registered in the Oslo metropolitan area.

Overlay and Number Portability Considerations

Norway does not use overlay codes in the traditional sense; instead, the country employs a closed numbering plan with fixed-length numbers. Number portability is fully implemented, meaning that a subscriber may retain their 2190 number even if they move to a different operator or relocate outside Oslo, provided the service is still provided by a Norwegian operator. This can occasionally lead to a situation where a 2190 number is answered outside the Oslo region, but for most practical purposes, the prefix remains a reliable indicator of the original geographic allocation.

Caller Instructions

For local callers within Oslo, dialing the eight-digit number is sufficient. For callers elsewhere in Norway, the same eight-digit number is dialed without any trunk prefix. International callers must include the +47 country code. There are no special tariffs for calling a 2190 number; standard rates for fixed-line calls apply, depending on the caller's operator and subscription plan. Emergency services (110, 112, 113) are always free and use short codes, unrelated to geographic prefixes.