Area Code 258 – Viana do Castelo
The phone area code for Viana do Castelo is 258 (international format +351258). Browse local exchange codes (NXX) and carrier assignments below.
📞 Exchange Codes (NXX) for Area Code 258
Select a central office code to view local carrier data and detailed information
📍 Geographic Location of Viana do Castelo
Geographic Coverage and Administrative Jurisdiction
The +351 258 country-code/area-code combination designates the geographic numbering area of Viana do Castelo, a district in the Norte region of Portugal. This area code covers the city of Viana do Castelo itself, the district capital, as well as the surrounding municipalities of Caminha, Vila Praia de Âncora, Ponte de Lima, Ponte da Barca, Arcos de Valdevez, and Paredes de Coura. The code is allocated to the northern coastal region of Portugal, bordering Spain to the north and the Atlantic Ocean to the west.
Administratively, the area is part of the Comunidade Intermunicipal do Alto Minho, and the code is assigned to fixed-line services (PSTN and VoIP) within this geographic region. It is important to note that while the code is geographically tied to this area, number portability allows subscribers to retain their 258 numbers even if they relocate outside the region, provided they remain with the same service provider or switch providers without changing numbers.
Dialing Formats and Caller Instructions
For callers within Portugal, the national trunk prefix 0 is used before the area code, followed by the subscriber number. The full national significant number (NSN) is 258 XXX XXX (9 digits including the leading 0). For example, to call a fixed line in Viana do Castelo from Lisbon, you would dial: 0 258 XXX XXX.
For international callers, the Portuguese country code +351 is used, and the leading trunk prefix 0 is dropped. Thus, an international call from the United States or the United Kingdom would be formatted as: +351 258 XXX XXX. This format is consistent with ITU-T E.164 recommendations.
Local calls within the same area code may be made using only the 9-digit subscriber number (without the area code) in some legacy systems, but the current standard in Portugal requires the full national number for all calls, including local ones, due to the implementation of closed numbering plan. Therefore, always dial the full number.
Overlay and Numbering Plan Considerations
As of the latest ITU-T national numbering plan, there is no overlay code for the Viana do Castelo area. The 258 code is exclusively assigned to this geographic region. However, due to the growth of VoIP services, many businesses and residents may have numbers that appear to be geographic but are actually routed over IP networks. This does not affect the dialing format.
For callers from outside Portugal, it is essential to use the international prefix of the originating country (e.g., 00 from most European countries, 011 from North America) before dialing +351 258. For example, from the UK, you would dial 00 351 258 XXX XXX.