Telephone numbers in Luxembourg

Telephone numbers in Luxembourg employ a closed dialling system, whereby all numbers are dialed in the same format whether from within Luxembourg or from abroad. There is no trunk prefix like "0".

The incumbent operator employed an open numbering plan with numbers of varying lengths, where a two-digit area identifier is followed by one to four digits, all six digits forming the subscriber number. This was changed by the introduction of a new numbering plan in 1999.^[1] Telephone numbers introduced since May 2000 by the incumbent operator begin with "2" (generally 26, 24 and recently 27^[2]) followed by two to six digits. The area identifier is still present and generally following the 26, 27 or 24, however numbers can be ported to any other area.

• 79 xxxx (example number in Consdorf)
• +352 79 xxxx (when dialed from outside Luxembourg)
• 2679 xxxx (example number in Consdorf for new lines since May 2000)
• +352 2679 xxxx (when dialed from outside Luxembourg)
• 4 xxx xx (example number in Luxembourg City)
• +352 4 xxx xx (when dialed from outside Luxembourg)

In Luxembourg, PBX extensions were generally appended to the main number, hence the need for an open numbering plan. As more PBXs were installed in offices in Luxembourg compared to areas with almost exclusively residential customers, this led to the impression that numbers in Luxembourg City would be longer than six digits. The regulator therefore decided that new phone numbers must be eight digits long including the extension. In order to fulfill this requirement, operators have to shorten a customer's phone number to 3-6 digits, to allow 2-5 digit extensions.