Area Code 31 – Constantine

Overview of Algeria's +213 31 Geographic Prefix

The international dialing code +213 31 is assigned to the wilaya (province) of Constantine, a major cultural and economic hub in northeastern Algeria. As a geographic prefix under the ITU-T E.164 numbering plan, it routes calls to fixed-line subscribers within the Constantine telephone exchange area. Constantine is the capital of the Constantine Province and is often referred to as the 'City of Bridges' due to its dramatic ravines and historic bridges. The prefix 31 covers the city itself and its surrounding administrative districts, including the communes of El Khroub, Didouche Mourad, and Hamma Bouziane.

Dialing Formats

To call a Constantine fixed-line number, the correct dialing format depends on the caller's location:

• Domestic calls (within Algeria): Dial 031 XXXX XX (the trunk prefix 0 is used before the area code). For example, a local number might be 031 12 34 56.
• International calls (from outside Algeria): Dial +213 31 XXXX XX or 00 213 31 XXXX XX (depending on the international access code of the originating country). For instance, calling from the US: 011 213 31 12 34 56.

Note that the leading '0' used in domestic dialing is omitted when dialing from abroad; the country code +213 replaces it.

Numbering and Overlay Considerations

Algerian fixed-line numbers typically consist of 8 digits after the country code, with the first two digits representing the geographic area code. In Constantine, numbers follow the pattern 31 XX XX XX (total 8 digits). As of the latest numbering plan updates, there are no overlay codes in Constantine; the 31 prefix remains exclusively for geographic fixed-line services. However, due to the growth of VoIP and mobile services, some numbers may be routed over IP networks, but the geographic significance remains for emergency services and regulatory purposes.

Caller Instructions

For local callers within Constantine, simply dial the 8-digit number without the area code if you are in the same zone? Actually, in Algeria, you must always dial the full 8-digit number including the area code, even for local calls. For example, to call a neighbor, you would still dial 031 12 34 56. Foreign callers should always use the international format +213 31 12 34 56.

When traveling in Algeria, ensure you have the correct international dialing prefix for your home country. If you are using a mobile phone, you can store the number as +213 31 12 34 56 to ensure proper routing.