Isabela II Electric Cooperative (ISELCO II) was organized and registered as a non-stock, non-profit electric cooperative with the National Electrification Administration (NEA) on February 25, 1978. Its organization was mandated by Republic Act No. 6038 which was enacted on August 4, 1969 and later amended by Presidential Decree No. 269 (PD 269), also known as the National Electrification ,Administration Charter, promulgated on August 6, 1973.

On June 22, 2007, ISELCO II also registered with the Cooperative Development Authority (CDA) by virtue of Republic Act No. 6938 (Cooperative Code) and Republic Act No. 6939 (Cooperative Development Authority Charter).