Area Code 81 – Oulu
The phone area code for Oulu is 81 (international format +35881). Browse local exchange codes (NXX) and carrier assignments below.
📞 Exchange Codes (NXX) for Area Code 81
Select a central office code to view local carrier data and detailed information
📍 Geographic Location of Oulu
Geographic Coverage and Administrative Jurisdiction
The Finnish national destination code (NDC) 81 is a geographic area code assigned to the city of Oulu and its surrounding municipalities in the Northern Ostrobothnia region. Oulu serves as the administrative capital of North Ostrobothnia and is one of Finland's most significant technology and education hubs, hosting a large number of ICT companies and the University of Oulu. The code covers the Oulu sub-region, including neighboring towns such as Kempele, Haukipudas, Kiiminki, Oulunsalo, and Yli-Ii, reflecting the historical boundaries of the local telephone exchange area.
Dialing Formats and Number Structure
Within Finland, calls to Oulu numbers are placed using the national trunk prefix 0 followed by the area code and the subscriber number. The complete national significant number (NSN) for a geographic line in Oulu is typically 10 digits long, consisting of the area code 81 and a 6- to 8-digit subscriber number, depending on the specific allocation. For example, a local Oulu number might be formatted as 08 123 4567 when dialed domestically. From abroad, callers must use the international prefix (e.g., 00 or +), followed by Finland's country code 358, then the area code without the leading zero, and the subscriber number. Thus, the same number would be dialed as +358 8 123 4567.
Overlay and Numbering Considerations
Currently, the Oulu area code 81 does not have an overlay code; it remains the sole geographic area code for the region. However, as with all Finnish geographic codes, number portability allows subscribers to retain their numbers when switching operators, but the geographic significance of the code is preserved. This means that a number starting with 81 may, in some cases, be served by a VoIP or mobile operator, but the number remains associated with the Oulu geographic area for routing and emergency services purposes.
Caller Instructions
- Local callers within Oulu: When dialing another local number, the area code may be omitted in some closed numbering plan scenarios, but it is recommended to always include the full national format (0 81 XXX XXXX) to ensure proper routing.
- Domestic callers from other parts of Finland: Dial 0 81 XXX XXXX.
- International callers: Dial your country's exit code (e.g., 00 from most European countries, 011 from North America), then 358 81 XXX XXXX.
For businesses and individuals in Oulu, the geographic code provides a local presence that can be important for trust and regional identity. When contacting Finnish services, always verify the complete number, as subscriber number lengths may vary.