Main Office

Brgy. Bigbiga, Santiago, Ilocos Sur
Telefax: 077 674 7267
0917 7775688(Globe)
0908 9677480(Smart)
ISD: 0917 7736574
Email: iseco_1974@yahoo.com.ph

Electric Billing Concern: iseco_billing@yahoo.com 
Any other concern call (077)632-3110 to 14

Sta. Cruz Sub-Office

Brgy. Bayugao West, Sta. Cruz
Hotline
0917 5793531(Globe)
0999 9955943(Smart)

Cabugao Sub-Office

Brgy. Sagayaden, Cabugao
Hotline: 0917 5793515

Vigan Sub-Office

Brgy. Ayusan Norte, Vigan City
Hotline: 0917-579-3517

Narvacan Sub-Office

Brgy. Nanguneg, Narvacan
Hotline: 0917 5793525(Globe)
               0960 3070840(Smart)

Candon Sub-Office

Brgy. Bagani Campo, Candon City
Hotline:  0917 5793527(Globe)
                0998 8668429(Smart)