IEMOP operates the Philippine Wholesale Electricity Spot Market (WESM) as the Independent Market Operator (IMO) in close coordination with the System Operator (SO). IEMOP is responsible for the commercial aspects of WESM transactions, while the SO takes care of the physical implementation of these market transactions. IEMOP runs the electricity market by, among other things, managing the registration of market participants, receiving generation offers, coming out with market prices and dispatch schedules of the generation plants, monitoring the day-to-day market trading, and handling billing, settlement, and collections.