Settlements

Settlements are the calculation, billing, and invoicing of charges and payments for market and transmission-related activities between market participants and the ISO. The settlement cycle follows a specific timeline and process for publication of statements, invoices, payment advices, dispute submittals, and payments. Various charging rates, processes, schedules, and documents are listed below.

Payments and charges

Many specific charge type categories are used within settlements and invoice processes according to involvement in the Markets and RC West.

Payments calendar

ISO charge codes

The ISO uses specific charge codes dependent on the type of charge.

Market and administrative charge rates

Grid Management Charge (GMC) rates

GMC is assessed to wholesale market customers to recover California ISO costs. This section contains current and historical GMC codes and rates and a sub section detailing the GMC unbundling process from 1998-2000.

GMC rates are based on the budget and grid management charge process.

View previous GMC charge rate documents

Emissions and start-up costs

Transmission access charge (TAC) rates

The current transmission access charge is a two-part rate for each megawatt hour of internal load and exports and is used to recover transmission revenue requirements. 

High voltage access charge rates
Title Updated
High Voltage Access Charge Rates Effective Jun 12, 2024
06/12/2024, 12:39 PM
High Voltage Access Charge Rates Effective Jan 01, 2024 (Revised May 24, 2024)
05/24/2024, 9:11 AM
High Voltage Access Charge Rates Effective Jan 01, 2022 (Revised Jun 30, 2023)
06/30/2023, 10:39 AM
High Voltage Access Charge Rates Effective Jun 13, 2022 (Revised June 30, 2023)
06/30/2023, 10:39 AM
High Voltage Access Charge Rates Effective Jun 13, 2023
06/22/2023, 9:29 AM
High Voltage Access Charge Rates Effective Jan 01, 2023 (Revised Jun 09, 2023)
06/09/2023, 9:39 AM
High Voltage Access Charge Rates Effective Oct 07, 2022 (Revised May 12, 2023)
05/12/2023, 9:12 AM
High Voltage Access Charge Rates Effective Jun 01, 2017 (Revised July 15, 2022)
07/15/2022, 9:47 AM
High Voltage Access Charge Rates Effective Jun 01, 2018 (Revised July 15, 2022)
07/15/2022, 9:47 AM
High Voltage Access Charge Rates Effective Jun 22, 2018 (Revised July 15, 2022)
07/15/2022, 9:47 AM
High Voltage Access Charge Rates Effective Apr 21, 2017 (Revised July 15, 2022)
07/15/2022, 9:47 AM
High Voltage Access Charge Rates Effective Jan 01, 2018 (Revised July 15, 2022)
07/15/2022, 9:47 AM
High Voltage Access Charge Rates Effective Apr 23, 2017 (Revised July 15, 2022)
07/15/2022, 9:47 AM
High Voltage Access Charge Rates Effective Sep 15, 2017 (Revised July 15, 2022)
07/15/2022, 9:47 AM
High Voltage Access Charge Rates Effective Mar 01, 2018 (Revised July 15, 2022)
07/15/2022, 9:47 AM
High Voltage Access Charge Rates Effective Jul 12, 2021 (Revised May 18, 2022)
05/25/2022, 9:07 AM
High Voltage Access Charge Rates Effective Jul 01, 2020 (Revised Dec 01, 2021)
12/01/2021, 12:22 PM
High Voltage Access Charge Rates Effective Aug 12, 2020 (Revised Dec 01, 2021)
12/01/2021, 12:22 PM
High Voltage Access Charge Rates Effective Jan 08, 2021 (Revised Dec 01, 2021)
12/01/2021, 12:22 PM
High Voltage Access Charge Rates Effective Jan 01, 2021 (Revised Dec 01, 2021)
12/01/2021, 12:22 PM
High Voltage Access Charge Rates Effective Jun 13, 2020 (Revised Dec 01, 2021)
12/01/2021, 12:22 PM
High Voltage Access Charge Rates Effective Feb 01, 2021 (Revised Dec 01, 2021)
12/01/2021, 12:22 PM
High Voltage Access Charge Rates Effective Apr 23, 2020 (Revised Dec 02, 2020)
12/02/2020, 7:53 AM
High Voltage Access Charge Rates Effective Jan 01, 2020 (Revised Jul 31, 2020)
07/31/2020, 9:36 AM
High Voltage Access Charge Rates Effective Feb 29, 2020 (Revised Jul 31, 2020)
07/31/2020, 9:36 AM
High Voltage Access Charge Rates Effective Mar 01, 2019 (Revised Jul 16, 2020)
07/16/2020, 10:42 AM
High Voltage Access Charge Rates Effective Jun 01, 2019 (Revised Jul 16, 2020)
07/16/2020, 10:42 AM
High Voltage Access Charge Rates Effective May 01, 2019 (Revised Jul 16, 2020)
07/16/2020, 10:42 AM
High Voltage Access Charge Rates Effective Jan 01, 2019 (Revised Jul 16, 2020)
07/16/2020, 10:42 AM
High Voltage Access Charge Rates Effective Sep 23, 2019 (Revised Jul 16, 2020)
07/16/2020, 10:42 AM
High Voltage Access Charge Rates Effective Jul 25, 2018 (Revised Oct 16, 2018)
10/16/2018, 2:50 PM
High Voltage Access Charge Rates Effective Jul 01, 2018
10/16/2018, 2:50 PM
High Voltage Access Charge Rates Effective Jan 1, 2017 (Revised Sep 26, 2017)
09/26/2017, 12:18 PM
High Voltage Access Charge Rates Effective Apr 20, 2017 (Revised Sep 26, 2017)
09/26/2017, 12:18 PM
High Voltage Access Charge Rates Effective Mar 1, 2017 (Revised Sep 26, 2017)
09/26/2017, 12:18 PM
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Wheeling access rates
Title Updated
Wheeling Access Rates Effective Jun, 12, 2024
06/12/2024, 12:39 PM
Wheeling Access Rates Effective Jan 01, 2024 (Updated May 24, 2024)
05/24/2024, 9:11 AM
Wheeling Access Rates Effective Jun 13, 2023
08/28/2023, 2:28 PM
Wheeling Access Rates Effective Jun 13, 2022 (Updated Jun 30, 2023)
06/30/2023, 10:39 AM
Wheeling Access Rates Effective Jan 01, 2022 (Updated Jun 30, 2023)
06/30/2023, 10:39 AM
Wheeling Access Rates Effective Jan 01, 2023 (Updated Jun 09, 2023)
06/09/2023, 9:39 AM
Wheeling Access Rates Effective Oct 07, 2022 (Updated May 12, 2023)
05/12/2023, 9:12 AM
Wheeling Access Rates Effective Jun 01, 2018 (Updated July 15, 2022)
07/15/2022, 9:47 AM
Wheeling Access Rates Effective Apr 23, 2017 (Updated July 15, 2022)
07/15/2022, 9:47 AM
Wheeling Access Rates Effective Mar 01, 2018 (Updated July 15, 2022)
07/15/2022, 9:47 AM
Wheeling Access Rates Effective Jan 01, 2018 (Updated July 15, 2022)
07/15/2022, 9:47 AM
Wheeling Access Rates Effective Jun 01, 2017 (Updated July 15, 2022)
07/15/2022, 9:47 AM
Wheeling Access Rates Effective Jun 22, 2018 (Updated July 15, 2022)
07/15/2022, 9:47 AM
Wheeling Access Rates Effective Sep 15, 2017 (Updated July 15, 2022)
07/15/2022, 9:47 AM
Wheeling Access Rates Effective Apr 21, 2017 (Updated July 15, 2022)
07/15/2022, 9:47 AM
Wheeling Access Rates Effective Jul 12, 2021 (Updated May 18, 2022)
05/18/2022, 8:54 AM
Wheeling Access Rates Effective Jan 08, 2021 (Updated Dec 01, 2021)
03/22/2022, 8:19 AM
Wheeling Access Rates Effective Feb 01, 2021 (Updated Dec 01, 2021)
03/22/2022, 8:19 AM
Wheeling Access Rates Effective Jan 01, 2021 (Updated Dec 01, 2021)
03/22/2022, 8:19 AM
Wheeling Access Rates Effective Apr 23, 2020 (Updated Dec 02, 2020)
12/28/2021, 11:00 AM
Wheeling Access Rates Effective Jul 01, 2020 (Updated Dec 01, 2021)
12/28/2021, 11:00 AM
Wheeling Access Rates Effective Jan 01, 2020 (Updated Apr 10, 2020)
12/28/2021, 11:00 AM
Wheeling Access Rates Effective Feb 29, 2020 (Updated Apr 10, 2020)
12/28/2021, 11:00 AM
Wheeling Access Rates Effective Jun 13, 2020 (Updated Dec 01, 2021)
12/28/2021, 11:00 AM
Wheeling Access Rates Effective Aug 12, 2020 (Updated Dec 01, 2021)
12/28/2021, 11:00 AM
Wheeling Access Rates Effective May 01, 2019 (Updated Jul 16, 2020)
07/16/2020, 10:42 AM
Wheeling Access Rates Effective Sep 23, 2019 (Updated Jul 16, 2020)
07/16/2020, 10:42 AM
Wheeling Access Rates Effective Jan 01, 2019 (Updated Jul 16, 2020)
07/16/2020, 10:42 AM
Wheeling Access Rates Effective Mar 01, 2019 (Updated Jul 16, 2020)
07/16/2020, 10:42 AM
Wheeling Access Rates Effective Jun 01, 2019 (Updated Apr 10, 2020)
04/10/2020, 10:34 AM
Wheeling Access Rates Effective Jul 25, 2018 (Updated Oct 16, 2018)
10/16/2018, 2:50 PM
Wheeling Access Rates Effective Jul 01, 2018
10/16/2018, 2:50 PM
Wheeling Access Rates Effective Jan 1, 2017 (Updated Sep 26, 2017)
09/26/2017, 12:18 PM
Wheeling Access Rates Effective Apr 20, 2017 (Updated Sep 26, 2017)
09/26/2017, 12:18 PM
Wheeling Access Rates Effective Mar 1, 2017 (Updated Sep 26, 2017)
09/26/2017, 12:18 PM
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View previous wheeling access charge rate documents

Submittal requirements for participating transmission owner rate changes

Amendment 60 - must offer waiver denial reports

Other processes

Reliability Must Run (RMR)

Settlement information for the annual agreements between the ISO and qualified generators.

Reliability Must Run (RMR) reporting

Disputes

Submit a settlement dispute form in CIDI*

*For scheduling coordinators only

Credit policy

The credit policy is detailed in the ISO Tariff and the Business Practice Manual for Credit Management and Market Clearing. Consistent with the policy, market participants use the following forms to demonstrate that they meet the ISO minimum participation and financial security requirements and to request an unsecured credit limit.

Related application(s) and access

The CIDI user guide is available on the application page.

If you are a scheduling coordinator and need access to settlement statements, invoices, ISO bill determinant files and SaMC configuration output files, visit the MRI-S application page for more information and the user guide.

Related ISO Tariff and Business Practice Manuals
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