Area Code 27 – Sion
The phone area code for Sion is 27 (international format +4127). Browse local exchange codes (NXX) and carrier assignments below.
📞 Exchange Codes (NXX) for Area Code 27
Select a central office code to view local carrier data and detailed information
📍 Geographic Location of Sion
Geographic Coverage and Administrative Jurisdiction
The Swiss area code +41 27 is a geographic National Destination Code (NDC) assigned to the canton of Valais (Wallis) in southwestern Switzerland. This mountainous region, part of the Rhône Valley, includes the administrative capital Sion (Sitten in German), along with key municipalities such as Brig-Glis, Martigny, Monthey, and Sierre. The code also serves the renowned alpine resorts of Zermatt, Verbier, and Crans-Montana, which are significant for tourism and international business. As a geographic code, +41 27 is tied to the physical PSTN network infrastructure, although calls to these numbers may be routed over IP backbones by carriers. The area is linguistically diverse, with French predominant in the west and German in the east, but the dialing code remains uniform across the entire canton.
Dialing Formats and Caller Instructions
Within Switzerland, calls to any number in the 27 region require the trunk prefix 0 followed by the NDC and the subscriber number. For example, a local call from within the canton to a Sion landline would be dialed as 027 123 45 67. However, from a mobile phone or from outside the Valais region, the same number is dialed as 027 123 45 67 as well, because Swiss numbering uses a closed dialing plan for national calls. International callers must replace the leading zero with the Swiss country code +41, resulting in +41 27 123 45 67. When dialing from abroad, omit the trunk prefix and use the plus sign or the appropriate international access code (e.g., 011 from the US, 00 from most European countries).
Number Structure and Overlay Considerations
Swiss geographic numbers have a variable length, typically 9 digits after the country code, including the NDC. In the +41 27 region, subscriber numbers usually consist of 7 digits, making the full national number 9 digits (0 27 XXX XX XX). There is no overlay code in this area; the 27 prefix is exclusively used for the Valais canton. The numbering plan is managed by the Federal Office of Communications (OFCOM), and number portability is available, allowing subscribers to retain their numbers when changing providers within the same geographic area. However, geographic numbers cannot be moved outside the designated region.
Practical Usage for Local and Foreign Callers
For businesses operating in the Valais, having a +41 27 number establishes a local presence and can reduce call costs for customers within the region. For callers, it is important to note that calls to Swiss geographic numbers are typically charged at standard landline rates, which may vary depending on the caller's telecom provider. When calling from a mobile phone, charges may be higher, and roaming charges apply for international callers. Always verify the complete number before dialing, as Swiss numbers do not have a fixed length for the subscriber portion, but the total length after the country code is consistent.