Area Code 87 – Oulu
The phone area code for Oulu is 87 (international format +35887). Browse local exchange codes (NXX) and carrier assignments below.
📞 Exchange Codes (NXX) for Area Code 87
Select a central office code to view local carrier data and detailed information
📍 Geographic Location of Oulu
Geographic Coverage and Administration
The Finnish national destination code (NDC) 87 is a geographic area code assigned to the city of Oulu and its surrounding region in Northern Finland. Administratively, this code falls under the jurisdiction of the Finnish Transport and Communications Agency (Traficom), which oversees the national numbering plan in accordance with ITU-T E.164 recommendations. The code 87 serves the Oulu sub-region, which includes the municipalities of Hailuoto, Kempele, Liminka, Lumijoki, Muhos, Oulu, and Tyrnävä. As the largest city in Northern Finland, Oulu is a major technological and educational hub, and the 87 code is used for fixed-line PSTN and VoIP services within this area.
Dialing Formats and Caller Instructions
For local callers within Finland, the national format requires dialing the trunk prefix '0' followed by the area code '87' and the subscriber number. The complete national significant number (NSN) for a fixed-line subscriber in Oulu is typically 9 digits, excluding the trunk prefix. For example, a local number might be formatted as 08 712 3456 when dialed domestically. International callers must replace the trunk prefix with Finland's country code, resulting in the format +358 8 712 3456. It is important to note that the leading '0' is omitted when dialing from abroad. When calling within the Oulu area, it is possible to use abbreviated local dialing (without the area code) for calls between subscribers in the same exchange, but this practice is becoming less common with the proliferation of VoIP and mobile services.
Overlay and Numbering Considerations
Currently, there is no overlay code for the Oulu region; the 87 code remains the sole geographic code for this area. However, due to the increasing demand for numbers and the transition to IP-based telephony, Traficom has implemented number portability, allowing subscribers to retain their 87 numbers when switching providers, even if the service is delivered via VoIP. This means that a call to an 87 number may terminate on a VoIP network, but the geographic significance of the code is retained for administrative and emergency service routing purposes. For callers, this implies that dialing an 87 number is always treated as a national call, regardless of the actual location of the called party.
Practical Guidance for Callers
For local callers: dial '0' followed by '87' and the subscriber number. For international callers: dial your country's exit code, then Finland's country code '358', then '8' (without the leading '0'), followed by the subscriber number. Always ensure you have the correct subscriber number, as the area code is essential for routing. For emergency services, always dial 112, which is the single European emergency number, regardless of the area code.