Area Code 31 – Isfahan province

Overview of Area Code +98 31

Area code 31 is the geographic National Destination Code (NDC) assigned to the province of Isfahan in Iran. Under the ITU-T E.164 international numbering plan, the full country calling code for Iran is +98, so numbers in this region are dialed internationally as +98 31 XXX XXXX. Domestically, callers within Iran dial 031 followed by the eight-digit subscriber number, omitting the leading international access code. This code covers the provincial capital, Isfahan city, as well as surrounding municipalities and districts within the province.

Geographic Coverage and Jurisdiction

The 31 area code serves the entire Isfahan province, which is located in central Iran. Key cities and towns within this code include Isfahan (the provincial capital), Kashan, Najafabad, Khomeyni Shahr, Shahin Shahr, Mobarakeh, Falavarjan, and Shahreza. The province is one of Iran's most populous and industrially significant regions, with a mix of urban and rural areas. The code is administered by the Telecommunications Company of Iran (TCI) under the regulatory oversight of the Communications Regulatory Authority (CRA).

Dialing Formats and Instructions

• Local calls (within Isfahan province): Dial the 8-digit subscriber number directly, without the area code. For example, if the number is 031-12345678, locally you would dial 12345678.
• Domestic long-distance calls (from other provinces in Iran): Dial 0 followed by the area code and subscriber number: 031 12345678.
• International calls from abroad: Dial your country's international access code (e.g., 00 or +), then Iran's country code 98, then the area code 31 (without the leading 0), and the 8-digit subscriber number: +98 31 12345678.
• Calls from a mobile phone in Iran: Mobile users can dial the full domestic format 031 12345678 regardless of their location, as mobile networks route calls based on the full number.

Numbering Structure and Overlay Considerations

Subscriber numbers in the Isfahan area code are eight digits long, following the pattern 031-XXXX XXXX. This structure is consistent with other major Iranian geographic codes. As of the latest updates, there are no overlay codes in Isfahan; the 31 code is the sole geographic code for the province. However, due to increasing demand for telecommunication services, the CRA may introduce additional numbering resources in the future. For now, all fixed-line numbers in the province fall under the 31 NDC.

Caller Instructions and Practical Tips

For local callers within Isfahan, omitting the area code for local calls is standard practice, but it is always safe to use the full domestic format (031) when dialing from any location to avoid confusion. For international callers, it is crucial to drop the leading zero of the area code when adding the +98 country code. For example, a number written as 031-12345678 domestically becomes +98 31 12345678 internationally. This distinction is essential to ensure successful call completion.