New Uncompetitive Intertie Zone Designations to Come into Effect
October 9, 2025
The IESO has determined that new Uncompetitive Intertie Zone (UIZ) designations are needed effective October 14. The IESO evaluates intertie zones on a quarterly basis, checking for factors that may give market participants an unfair advantage.
UIZs may then be used to apply after-the-fact settlement charges to correct imbalances.
This round of designations is based on a review of intertie schedules between July 1, 2025, and September 30, 2025. To view all current UIZ designations, visit the Uncompetitive Intertie Zones webpage.