Area Code 310 – Mobile Network

Overview of Colombia's Mobile Prefix 310

In Colombia, the national numbering plan adheres to the ITU-T E.164 standard, with a country calling code of +57. Mobile numbers are non-geographic, meaning they are not tied to a specific city or region. The prefix 310 is one of the earliest mobile prefixes assigned in Colombia, originally allocated to the state-owned operator Colombia Móvil (branded as Ola), which later became part of Tigo (a subsidiary of Millicom). Today, the prefix 310 is operated by Tigo Colombia, one of the country's major mobile network operators (MNOs).

Colombian mobile numbers consist of ten digits in total: the national significant number (NSN) includes the prefix (e.g., 310) followed by a seven-digit subscriber number. When dialing from abroad, the international format is +57 310 XXX XXXX, where the leading '0' (if any) is omitted. Within Colombia, callers can dial the ten-digit number directly, e.g., 310 123 4567, without any trunk prefix.

Number Portability and Routing

Colombia implemented mobile number portability (MNP) in 2011, allowing subscribers to retain their numbers when switching operators. Consequently, a number starting with 310 may no longer be served by Tigo; it could have been ported to another MNO such as Claro, Movistar, or WOM. Therefore, the prefix does not guarantee the current operator, and routing decisions are made by the national database. For SMS and voice calls, the network queries the portability database to route the call correctly.

Dialing Instructions

• Domestic calls (within Colombia): Dial the ten-digit mobile number: 310 XXX XXXX.
• International calls (from abroad): Dial your country's exit code, then 57, then the ten-digit mobile number (omitting any leading zero): +57 310 XXX XXXX.
• International SMS: Use the same international format: +57 310 XXX XXXX.

All Colombian mobile numbers are allocated for voice, SMS, and data services. As a non-geographic prefix, 310 numbers are not tied to a specific department or city, enabling users to keep their numbers when relocating within the country.

Regulatory and Technical Notes

The Comisión de Regulación de Comunicaciones (CRC) oversees the numbering plan and has implemented measures to ensure efficient use of numbering resources. The 310 prefix is part of the 300-399 range designated for mobile services. With the growth of mobile subscriptions, additional prefixes have been introduced, but 310 remains a recognizable and widely used prefix. For enterprises, verifying the current operator of a 310 number is essential for interconnect agreements and SMS marketing campaigns, as termination rates may vary by operator.