System Reliability

The mandatory enforcement dates of NERC reliability standards and NPCC criteria are governed by Chapter 5, Sections 1.2.6 and 1.2.7 of the Market Rules. The following milestones are used to determine the enforcement dates for NERC standards in Ontario:

• NERC Board of Trustees adopts the standard
• Ontario Energy Board Review Process starts
• Ontario Energy Board Review Process ends
• The standard mandatory enforcement date in Ontario is determined
• The standard inactive date in Ontario is determined          

Deferred Ontario Effective Dates due to COVID-19

Revised IESO Generator Verification Testing Dates due to COVID-19

Notice to Market Participants: Completion of Ontario GIC Assessment for TPL-007-4, R5 and R9

Notice to Market Participants: Completion of Ontario GIC Assessment for TPL-007-4, R4 and R8

Implementation plans for certain reliability standards

• Ontario Enforcement Dates for NERC Reliability Standards and NPCC Criteria (Updated April 15, 2025)
• EOP-011-2, EOP-011-3, EOP-011-4 (Updated September 24, 2024)
• EOP-012-1, EOP-012-2 (Updated September 24, 2024)
• Please note that on April 4, 2025, EOP-012-3 received NERC Board of Trustees approval under a longstanding special rule for standards addressing regulatory directives in Section 321.5 of the NERC Rules of Procedure. However, the EOP-012-3 standard did not achieve the necessary votes for approval by the ballot body and will therefore not come into effect in Ontario as per the Market Rules. A new version of this standard that will include a Canadian variance is under development and will replace EOP-012-2 which will remain in effect in Ontario until then. (Updated November 5, 2025)
• PRC-002-2 (Updated September 2021)
• PRC-005-2(i) and PRC-005-6 (Updated January 12, 2022)
• PRC-019-2; PRC-024-2; MOD-025-2; MOD-026-1 and MOD-027-1 (Updated October 29, 2024)
• PRC-025-2
• PRC-028-1 (Updated March 4, 2025)
• TPL-007-4 (Updated May 30, 2024)
• TPL-008-1 (Updated September 15, 2025)