Telco OI (commonly known as Only) is a mobile network operator in French Departments and Territories in the Indian Ocean assigned PLMN code 647-02 by the national telecommunications authority.

The MCC 647 identifies French Departments and Territories in the Indian Ocean, while MNC 02 uniquely identifies this operator within the country. Together they form the PLMN (Public Land Mobile Network) identifier used by mobile devices for network selection, SIM card identification, and international roaming.

This assignment was last reported in ITU Operational Bulletin #1280 (Nov. 15, 2023). Search all MCC/MNC codes or view all French Departments and Territories in the Indian Ocean operators .