Avista also provides energy bill payment assistance programs and payment options for qualifying customers. Information about these customer programs and options is available at www.myavista.com. About Avista Corp. Avista Corp. is an energy company involved in the production, transmission and distribution of energy as well as other energy-related businesses. Avista Utilities is the operating division that provides electric service to 389,000 customers and natural gas to 357,000 customers. Its service territory covers 30,000 square miles in eastern Washington, northern Idaho and parts of southern and eastern Oregon, with a population of 1.7 million.