Area Code 77 – Troms
The phone area code for Troms is 77 (international format +4777). Browse local exchange codes (NXX) and carrier assignments below.
📞 Exchange Codes (NXX) for Area Code 77
Select a central office code to view local carrier data and detailed information
📍 Geographic Location of Troms
Geographic Coverage and Administrative Jurisdiction
The Norwegian country code +47, assigned under ITU-T E.164, is used for all national numbering plan areas. The prefix 77 is a geographic National Destination Code (NDC) allocated to the region of Troms, located in Northern Norway. This area encompasses the administrative county of Troms (Troms og Finnmark until 2024, now split into Troms and Finnmark), including the city of Tromsø, which serves as the regional capital and largest urban center. The numbering area covers both mainland municipalities such as Harstad, Finnsnes, and Bardu, as well as island communities like Senja and Kvaløya. The 77 prefix is used for fixed-line PSTN services, and numbers under this prefix are typically 8 digits long when dialed nationally, following the format 77 XX XX XX.
Dialing Formats and Caller Instructions
For local callers within Norway, the complete national number must be dialed, including the leading '77'. For example, a fixed-line subscriber in Tromsø would be reached by dialing 77 XX XX XX. There is no local dialing without the area code; the entire 8-digit number is always required. For international callers, the Norwegian country code +47 is added, and the leading '0' is not used (Norway does not use a trunk prefix). Thus, an international caller would dial +47 77 XX XX XX. When calling from a mobile phone in Norway, the same national format applies. It is important to note that Norway has implemented number portability, so a number starting with 77 may have been ported to a different geographic region or even to a mobile network, but the original geographic association remains for administrative purposes.
Overlay and Numbering Plan Considerations
Norway does not use overlay codes; instead, the country uses a closed numbering plan with 8-digit subscriber numbers for geographic areas. The 77 prefix is one of several geographic NDCs, and there is no area code splitting or overlay in Troms. The Norwegian Communications Authority (Nkom) manages the numbering plan, ensuring that geographic numbers are used for fixed-line services, although VoIP providers may also offer numbers with geographic prefixes. For callers, this means that dialing a 77 number will route to the Troms region, but the actual physical location of the called party may vary due to number portability.
Practical Usage and Examples
To illustrate, a typical number in Tromsø might be 77 60 00 00. A caller from Oslo would dial 77 60 00 00 (national format). A caller from the United States would dial 011 47 77 60 00 00 (international prefix + country code + number). For businesses, having a 77 number establishes a local presence in Troms, which can be beneficial for customer trust and local marketing. However, with the rise of IP telephony, geographic numbers are no longer strictly tied to physical lines, but they still carry the regional identity.