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Market Oversight and Compliance

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Email: macd@ieso.ca.​

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Compliance Enforcement

Market Monitoring

The IESO is authorized by the Electricity Act, 1998 to make rules governing the power grid and the electricity market.

Oversight and compliance with the market rules is key to the operation of an efficient and reliable electricity market and power grid. The IESO's Market Assessment and Compliance Division (MACD) monitors the operation of Ontario's electricity market and fosters compliance with the Ontario market rules and North American reliability standards. It does this through its prevention, monitoring, auditing, investigation, and enforcement activities.

Compliance Enforcement

MACD is responsible for investigating and determining whether market participants are compliant with the IESO market rules. In carrying out its compliance function, it oversees activities and conduct in the Ontario electricity market through the monitoring for anomalous outcomes and the investigation of potential breaches of the rules, which include North American reliability standards.

In some cases, MACD conducts enforcement of the rules in order to foster compliance and deter non-compliance. Market participants who breach the market rules may be subject to sanctions if appropriate. In addition, MACD performs audits and other reviews which can lead to the recovery of payments received by market participants. It also works with other IESO business units on market participant communications, education and training to promote compliance.

Market Monitoring

The IESO, through a special MACD assessment unit, also supports the Market Surveillance Panel to monitor, investigate and report on the activities and conduct of market participants and the IESO in Ontario's electricity market. Although the Panel reports directly to the Ontario Energy Board, it relies on effective market monitoring by MACD in order to carry out its responsibilities. Additional information about the Panel and MACD's role in supporting it are provided in the Market Monitoring section.


The IESO is authorized by the Electricity Act, 1998 to make rules governing the power grid and the electricity market.