BILECO was granted authority to operate in the seven districts of the province of Biliran, namely: Biliran, Naval, Almeria, Kawayan, Cabucgayan, Caibiran and Culaba, collectively called its Franchise Area. Likewise, it operates in off-grid island barangays of Mabini and Libertad in Higatangan island under the municipality of Naval through a diesel power plant which operates for 8 hours between 3:00 to 11:00 pm. Its area coverage covers a total land area of 508.18 sq km (196.2 sq mi), comprised of 117 barangays. It achieved its 100% barangay energization on October 21, 2006 after the successful energization of the two island barangays of Mabini and Libertad in Higatangan island.

Here are some quick facts about the seven districts as of December 31, 2021: