Settlement Process

Reading and Collecting Meter Data

Central to the IESO settlements systems is the meter data management system which is responsible for collecting raw data from over 1800 metering installations around the province. The revenue meters measure and record all energy injected and withdrawn from the grid for each five-minute interval. The data undergoes the validation, editing and estimation (VEE) process before it is ready for settlement.

The IESO uses the settlement-ready data to determine revenue owed to suppliers, and costs for consumers, as well as associated electricity charges.

The IESO uses the data from the reconciliation process to produce preliminary settlement statements, final settlement statements, and invoices for participants.

Market participants with revenue meters can access their daily meter data on the IESO Participant Reports Site.

Market Participant Invoicing

Market participants receive a daily statement for each trade day, and a monthly invoice on their Participant reports site. See Physical Market Schedule and Payments Calendar for the timelines to receive settlement statements, invoices and to submit or receive payments.

Preliminary Settlement Statement

The preliminary (first) statement for each trade day is available ten business days after each trade day. If participants have any disagreement with the statement, they must submit a Notice of Disagreement to the IESO using Online IESO within four business days of receiving their preliminary statement.

Final Settlement Statement

The final statement for each trade day is available ten business days after the preliminary statement is available.

Data Files

The data file that accompanies the preliminary and final settlement statements for each trade day provides additional information that will help participants to reconcile their statements.


Invoices are available once a month, published ten business days after the end of the calendar month. The invoice is based on final settlement statement data for the first half of the month and on preliminary settlement statement data for the last half of the month. Preliminary settlement statement issues will typically be corrected on the final settlements statement on the following months invoice. The IESO also processes settlements with LDCs for costs related to the Conservation First Framework as part of the monthly market invoice.

Transferring Funds

Market participants are required to pay their IESO invoice within two business days of receiving the invoice. Suppliers will receive their funds within four business days of receiving their invoice from the IESO.

Settling the Financial Market

The IESO issues preliminary and final settlement statements and invoices for the Transmission Rights auction, the IESO’s only financial market, but the timelines are shorter. See Financial Market Settlement and Payments Calendar.

Related Tools

For statements and invoices: Participant report site

Key settlement and payment dates: Market Calendars

File Notice of Disagreement: Online IESO

Access to meter data: Participant report site

Documents: IESO Charge Types and Equations and Format Specifications for Settlement Statement Files and Data Files

Training Workbooks: Settlement Statements and Invoices and Revenue Metering