Urgent Market Rule Amendments

Amendments to the market rules can also be decided by the Urgent Rule Amendment Committee or the IESO Board. Urgent market rules amendments must be ratified by the IESO Board and come into force on the date specified in the market rule amendment proposal.

Market Rule Chapter/Section Title Related Documents Last Updated
MR-00486-R00
 Chapter 0.9 Sections 3.3 and 3.5 Corrections to the Day-Ahead Market Balancing Credit and Real-Time Make-Whole Payment Reasons of the IESO Board

Resolution of the IESO Board

Consumer Impact Assessment

OEB Letter		 26-May-2025
MR-00485-R00
 Chapter 10 and 0.10 Section 4.6 Tariff Response Charge for Exports to the United States Reasons of the IESO Board

Resolution of the IESO Board

Consumer Impact Assessment		 10-Mar-2025
MR-00398-R00 Chapter 9
Section 3.3.2 		Correction to Limiting Payments to Exports during Negative Prices   27-Sept-2012
MR-00380-R00-R01 Chapter 9
Sections 3.5.1A and 3.5.1D 		Non-transmission Related Constrained Off Payments   31-Mar-2011
MR-00373-R00 Chapter 9
Section 3.5.1C 		Suspend CMSC for Constrained Off Dispatchable Loads   27-Aug-2010
MR-00323-R00 Chapter 9
Section 3.8A 		Day-Ahead Intertie Offer Guarantee Adjustment   27-Jun-2006
MR-00322-R00-R01 Chapter 9
Section 3.8A 		Day-Ahead Intertie Offer Guarantee and Real-Time negative CMSC   9-Jun-2006
MR-00315-R00 Chapter 9
Section 3.5.8 		Eliminate Congestion Management Settlement Credit Payments for Linked Wheeling Through Transactions   7-Apr-2006
MR-00309-R00 Chapter 7
Sections 2.2.10 and 2.2.20 		Provision of Black Start Capability by Self-Scheduling and Transitional Scheduling Generators   7-Dec-2005
MR-00243-ROO Chapter 7
Appendix 7.6 		Urgent Market Rule Amendment: Limiting CMSC Payments to Constrained-off Exports on Uncontested Export Interties   21-Aug-2003
MR-00239-R00 Chapter 9
Section 3.5 		Eliminate CMSC Payments Associated with Negative Priced Offers   26-Jun-2003
MR-00238-R00 Chapter 7
Section 8.4 		Correcting Inappropriate Charges and Payments that may Occur Under Administrative Pricing   5-Jun-2003
MR-00233-R00 Chapter 9
Section 5.1 		Urgent Amendment to Market Power Mitigation Rebate Rules   2-May-2003
MR-00215-R00 Chapter 2
Section 5.8.2A 		Suspension of Deemed Credit Downgrade Resulting from Credit Watch Warning   19-Nov-2002
MR-00214-R00 Chapter 9
Section 1.2 		Bill 210 Consequential Market Rule Amendments   13-Dec-2002
MR-00204-R00-R01 Chapter 9
Section 3.8A, 4.8 		Eliminate Payment of Intertie Offer Guarantee for Wheeling Transactions   1-Aug-2002

Any individual may identify the need for an urgent rule amendment using the Market Rule Amendment Submission Form. Urgent rule amendments may be identified as a result of the occurrence of a specific event in the market that requires an immediate amendment to the market rules. An urgent amendment to the market rules can be required for one or more of the following reasons:

  • To avoid, reduce the risk of, or mitigate the effects of conditions that affect the ability of the integrated power system to function normally
  • To avoid, reduce the risk of, or mitigate the effects of the abuse of market power
  • To implement standards or criteria of a standards authority
  • To avoid, reduce the risk of, or mitigate the effects of an unintended adverse effect of a market rule

Each submission should clearly identify the area of the rules under question, state the proposal, provide reasons for the proposed change, explicitly indicate that the amendment is urgent and identify which criteria was applied to make this determination.

Please submit completed forms by email to rule.amendments@ieso.ca.