Settlement Reference Materials

The Market Renewal Program (MRP) will introduce a wide range of design changes to the market which will result in changes to over 140 settlement charge types out of the 278 charge types that exist in the Ontario electricity market. Some charge types will be retired, new ones will be introduced, and others will be amended, and these changes will impact each Market Participant type differently.

These changes are detailed in the updated market rules, market manuals, and technical interface documents. The following files can be downloaded from the ‘Market Settlements, Metering and Billing’ section of the MRP’s Implementation Phase documents web page:

  • Charge Types and Equations (MRP Version - updated January 29, 2024)
  • Format Specifications for Settlement Files and Data Files (MRP Version) (pending document - Target Release: Q2 2024)

Charge Type Mapping Summaries for Market Participants and LDCs

To assist Market Participants in preparing for these settlement changes, the IESO has prepared two transitional informational spreadsheets on settlement charges.

  1. The MRP Mapping Summary of Charge Types for all MPs shows how existing charge types connect to the new charge types under MRP. It groups similar charge types together based on a common function or purpose they serve. This document can be used as a supplementary resource to support your internal training efforts, as well as when updating your organization’s settlement systems and procedures.

    MRP Mapping Summary of Charge Types for all MPs (updated March 12, 2024)
  2. Local Distribution Companies (LDCs) have an additional responsibility of translating their market settlements into monthly bills for their customers. A separate Excel file is being developed for LDCs in collaboration with staff from the Ontario Energy Board (OEB) who regulates how variances related to these charges are tracked through Retail Settlement Variance Accounts (RSVA) and determines how the relevant IESO Charge Types are assigned to the applicable RSVAs. These details are still in development; any information in this file should be considered draft only, as it may change when formal OEB accounting guidance is issued to LDCs. LDCs should refer to both mapping summaries for a comprehensive understanding of settlement changes related to them.

    MRP Mapping Summary of Charge Types and Variance Accounts for LDCs (updated March 12, 2024)
    Note: this file is available upon request, by emailing

While the IESO updates these files periodically to aligned with any design updates leading up to MRP Go-Live, these files are intended to be supporting resources and will be retired when the new market is in-service. If there are any discrepancies between these mapping summaries, and the List of IESO Charge Types and Equations, Market Manual 5.5 and OEB Guidance documents related to MRP, the two IESO market-related documents and formal OEB guidance shall preside.