Area Code 85 – Bissen/Roost

Geographic Scope and Administrative Jurisdiction

The +352 85 prefix is a geographic National Destination Code (NDC) assigned to the Bissen and Roost area in central Luxembourg. Bissen is a commune in the canton of Mersch, while Roost is a small town within the commune of Bissen. These localities are situated in the valley of the Attert River, approximately 20 kilometers north of Luxembourg City. The prefix serves a predominantly residential and rural district, with local businesses and public services relying on this code for fixed-line telephony.

Dialing Formats and Number Structure

In Luxembourg, the national numbering plan follows a closed dialing plan, meaning the full national number (including the leading '85') must always be dialed, even for local calls. There is no trunk prefix like '0' used in many other countries. The complete national number for a subscriber in this area typically consists of the two-digit NDC '85' followed by a subscriber number of variable length, usually 3 to 5 digits, resulting in a total number length of 5 to 7 digits. For example, a local number might be 85 1234, which would be dialed as 85 1234 from anywhere within Luxembourg.

International Dialing Instructions

To call a fixed line in Bissen or Roost from abroad, callers must use Luxembourg's country calling code +352, followed by the NDC and the subscriber number, omitting any leading zeros (none exist in Luxembourg). For instance, to reach the number 85 1234, an international caller would dial +352 85 1234. When dialing from within Luxembourg, simply dial 85 1234. It is important to note that Luxembourg does not use area code overlays; each geographic region has a unique NDC, so there are no overlapping codes in this area.

Caller Guidance and Regulatory Notes

For local callers, the closed dialing plan means that even if you are physically located in Bissen and calling a neighbor, you must still include the '85' prefix. This is a common source of confusion for visitors from countries with open dialing plans. For international callers, ensure you have the correct country code and omit any initial '0' that might be part of the local notation (though not applicable here). The Luxembourg Institute of Regulation (ILR) oversees telecommunications numbering, and as of recent years, number portability allows subscribers to retain their geographic numbers when switching providers, though the geographic significance may remain for routing purposes.