Area Code 72 – Sør-Trøndelag
The phone area code for Sør-Trøndelag is 72 (international format +4772). Browse local exchange codes (NXX) and carrier assignments below.
📞 Exchange Codes (NXX) for Area Code 72
Select a central office code to view local carrier data and detailed information
📍 Geographic Location of Sør-Trøndelag
Geographic Coverage and Administrative Jurisdiction
The Norwegian country code +47, governed by the Norwegian Communications Authority (Nkom) under the ITU-T E.164 international numbering plan, allocates the geographic area code 72 to the former county of Sør-Trøndelag, now part of the Trøndelag region. This code serves the central part of Norway, with Trondheim as the principal city and administrative hub. The area encompasses municipalities such as Malvik, Melhus, Skaun, Klæbu, and Orkland, extending to coastal and inland districts. The prefix 72 is a geographic National Destination Code (NDC) tied to a specific PSTN exchange area, not a mobile or non-geographic service.
Dialing Formats and Caller Instructions
For domestic callers within Norway, the area code 72 is dialed as a trunk prefix '0' followed by the NDC and the subscriber number: 0 72 XX XX XXX. For example, a local number in Trondheim would be dialed as 072 XX XX XXX from other parts of Norway. Internationally, callers must use the country code +47 and drop the leading trunk zero: +47 72 XX XX XXX. For instance, a caller from abroad would dial +47 72 12 34 567 to reach a fixed-line subscriber in the region. It is important to note that Norwegian fixed-line numbers typically have 8 digits after the area code, and the total length of a national significant number is 8 digits.
Overlay and Numbering Considerations
Currently, there is no overlay code for the 72 area; the region uses the single NDC 72. However, as part of Nkom's number management, geographic numbers may be ported across operators, but they retain their geographic significance. The code is exclusively for fixed-line services, and VoIP services that use geographic numbers must adhere to the same dialing rules. For callers within the region, local calls may be dialed using only the subscriber number if the network supports it, but the recommended format for clarity is the full national format. Businesses in the area often list their numbers as +47 72 XX XX XXX to facilitate international contact.
Practical Usage and Examples
When calling a business in Trondheim from abroad, you would dial +47 72 55 10 00 (fictional example). From Oslo, you would dial 072 55 10 00. The prefix 72 is also used for fax lines and traditional PSTN services. For travelers, understanding that 72 is a geographic code helps in identifying the region of a fixed-line number, but it does not indicate the caller's location if the number has been ported to a VoIP service. Nonetheless, the code remains a reliable indicator of the original service area.