Area Code 31 – Buskerud
The phone area code for Buskerud is 31 (international format +4731). Browse local exchange codes (NXX) and carrier assignments below.
📞 Exchange Codes (NXX) for Area Code 31
Select a central office code to view local carrier data and detailed information
📍 Geographic Location of Buskerud
Geographic Coverage and Administrative Jurisdiction
The Norwegian country code +47, assigned under ITU-T E.164, is used for all telephony services in Norway. The area code 31 is a geographic National Destination Code (NDC) that routes calls to the traditional landline network in the historical county of Buskerud. Although administrative reforms in 2020 merged Buskerud into the larger Viken county, the telephony numbering plan still recognizes 31 as the designated code for this region. The code covers a mix of urban and rural areas, with the principal city being Drammen, Norway's seventh-largest municipality. Other notable towns served by this code include Kongsberg, Hønefoss, and Hokksund.
Primary Cities and Local Dialing Format
Within the 31 code area, subscribers are assigned numbers with a total length of eight digits when including the area code. The local number format is typically five digits after the area code, e.g., 31 XXX XX. For local calls within the same area code, callers can often dial only the five-digit subscriber number without the area code, depending on the specific operator's dialing plan. However, for calls from other regions within Norway, the full national significant number must be dialed: 31 XXX XX (without the leading trunk prefix 0, as Norway uses a closed numbering plan).
International Dialing Instructions
To reach a landline in Buskerud from abroad, callers must use the international prefix of their country (e.g., 00 from most European countries, 011 from North America) followed by Norway's country code +47, then the area code 31 and the subscriber number. The complete international format is +47 31 XXX XX. For example, a call to a business in Drammen would be dialed as +47 31 12 34 56. No trunk prefix is used in international dialing.
Overlay and Numbering Considerations
As of the latest ITU-T allocations, there is no overlay code for the 31 area; the code remains exclusive to the geographic region. However, number portability allows subscribers to retain their 31 numbers when switching operators, even if they move outside the area, which can occasionally lead to non-geographic usage. Callers should be aware that the cost of a call to a 31 number is typically the same as any other national landline call, and it may be included in flat-rate packages. For emergency services, the national number 112 is used, and it is independent of area codes.