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

California ISO Payments Calendar 202410/26/2023, 8:12 AM
California ISO Payments Calendar 202410/26/2023, 8:12 AM
ISO RMR Payments Calendar Tool05/24/2023, 10:54 AM
RC West Annual Payments Calendar10/29/2019, 8:50 AM

View previous payment calendars

ISO charge codes

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

ISO Charge Codes Matrix10/18/2023, 9:11 AM

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.

Title	Posted
Summary of Regional Transmission Organization Costs Effective Jan 01, 2024	12/20/2023, 9:44 AM
Grid Management Charge Rates for 2004-2024 Effective Jan 01 2024	12/18/2023, 3:02 PM
Grid Management Charge Rates for 2004-2023 Effective May 01 2023	04/21/2023, 9:16 AM
Summary of Regional Transmission Organization Costs Effective Jan 01, 2023	12/28/2022, 8:10 AM
Grid Management Charge Rates for 2004-2023 Effective Jan 01, 2023	12/20/2022, 9:00 AM
Grid Management Charge Rates for 2004-2022 Effective Nov 01 2022	10/24/2022, 8:40 AM
Grid Management Charge Rates for 2004-2022 Effective Aug 01 2022	07/18/2022, 7:53 AM
Summary of Regional Transmission Organization Costs Effective Jan 01, 2022	12/29/2021, 10:04 AM
Grid Management Charge Rates for 2004-2022 Effective Jan 01, 2022	12/20/2021, 11:11 AM
Summary of Regional Transmission Organization Costs Effective Jan 01, 2021	12/31/2020, 8:50 AM
Grid Management Charge Rates for 2004-2021 Effective Jan 01, 2021	12/22/2020, 2:00 PM
Grid Management Charge Rates for 2004-2020 Effective Oct 01, 2020	09/22/2020, 9:38 AM
Grid Management Charge Rates for 2004-2020 Effective Jun 01, 2020	05/19/2020, 9:52 AM
Summary of Regional Transmission Organization Costs Effective Jan 01, 2020	01/06/2020, 12:48 PM
Grid Management Charge Rates for 2004-2020 Effective Jan 01, 2020	12/23/2019, 11:06 AM
No results

View previous GMC charge rate documents

Emissions and start-up costs

Start-Up Cost Charge Analysis03/04/2008, 7:49 AM
Emissions Cost Invoice Template07/09/2010, 4:51 PM

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	Posted
High Voltage Access Charge Rates Effective Jun 12, 2024 (Revised Jun 26, 2024)	07/05/2024, 9:24 AM
High Voltage Access Charge Rates Effective Jan 01, 2024 (Revised Jun 26, 2024)	07/05/2024, 9:24 AM
High Voltage Access Charge Rates Effective Jul 01, 2024	07/05/2024, 9:24 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 Jan 01, 2022 (Revised Jun 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 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 Jan 01, 2018 (Revised July 15, 2022)	07/15/2022, 9:47 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 22, 2018 (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 Apr 21, 2017 (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 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 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 Jan 08, 2021 (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 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 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 Jun 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 Mar 01, 2019 (Revised Jul 16, 2020)	07/16/2020, 10:42 AM
High Voltage Access Charge Rates Effective Jul 01, 2018	10/16/2018, 2:50 PM
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 Mar 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 Jan 1, 2017 (Revised Sep 26, 2017)	09/26/2017, 12:18 PM
No results

View previous high voltage access charge rate documents

Wheeling access rates

Title	Posted
Wheeling Access Rates Effective Jun 12, 2024 (Updated Jun 26, 2024)	06/26/2024, 11:31 AM
Wheeling Access Rates Effective Jan 01, 2024 (Updated Jun 26, 2024)	06/26/2024, 11:31 AM
Wheeling Access Rates Effective Jul 01, 2024 R7	06/26/2024, 11:14 AM
Wheeling Access Rates Effective Jun 13, 2023	08/28/2023, 2:28 PM
Wheeling Access Rates Effective Jan 01, 2022 (Updated Jun 30, 2023)	06/30/2023, 10:39 AM
Wheeling Access Rates Effective Jun 13, 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 01, 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 08, 2021 (Updated Dec 01, 2021)	03/22/2022, 8:19 AM
Wheeling Access Rates Effective Jun 13, 2020 (Updated Dec 01, 2021)	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 Jul 01, 2020 (Updated Dec 01, 2021)	12/28/2021, 11:00 AM
Wheeling Access Rates Effective Apr 23, 2020 (Updated Dec 02, 2020)	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 Aug 12, 2020 (Updated Dec 01, 2021)	12/28/2021, 11:00 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 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 Jun 01, 2019 (Updated Apr 10, 2020)	04/10/2020, 10:34 AM
Wheeling Access Rates Effective Jul 01, 2018	10/16/2018, 2:50 PM
Wheeling Access Rates Effective Jul 25, 2018 (Updated Oct 16, 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
No results

View previous wheeling access charge rate documents

Submittal requirements for participating transmission owner rate changes

Video - Transmission Access Charge Process Improvements05/18/2024, 7:43 PM
Presentation - Transmission Access Change Process Improvements - Oct 26, 202010/27/2020, 11:23 AM

Settlement mitigation

Supporting information regarding settlement estimation methodology in the event of a system error.

Estimation of Invoice Interest Deviation for Trade Date 06-30-201907/03/2019, 10:35 AM
Estimation of RAAIM Settlement Beginning Trade Date May 1, 201706/18/2019, 8:06 AM
Estimation of Fifteen-Minute Market Instructed Imbalance Energy EIM for Trade Date Mar 28, 201904/02/2019, 12:51 PM
Estimation of MLC for Trade Date Mar 2, 201903/06/2019, 8:37 AM
Estimation of RAAIM Settlement April 2017 Monthly Statement07/17/2017, 3:35 PM
Estimation of EIM Transfer Quantities v4.006/26/2017, 8:00 AM
Estimation of Upward Ancillary Service Settlement05/10/2017, 8:33 AM
Estimation of Convergence Bidding CRR Adjustment Settlement04/27/2017, 10:34 AM
Estimation of Nodal and Resource Prices (Updated)03/14/2017, 4:27 PM
Estimation of Weekly Invoice Published Oct 26, 201610/26/2016, 10:48 AM
Estimation of Weekly Invoice Published Oct 19, 201610/19/2016, 4:07 PM
Estimation of Marginal Congestion Cost Breakdown Prices10/05/2016, 3:43 PM
Estimation of Weekly Invoice Published Jun 8, 201606/07/2016, 11:34 AM
Estimation of May 2015 T+9M Billing03/17/2016, 9:02 AM
Estimation of Weekly Invoice Published Aug 5, 201508/05/2015, 6:10 PM
Estimation of April 2015 T+55B Billing07/27/2015, 3:54 PM

View previous settlement mitigation documents

Amendment 60 - must offer waiver denial reports

Total Start-Up Cost: July 17, 2004 - March 31, 200905/14/2012, 12:15 PM
Total Minimum Load MWs of the Must-Offer Capacity05/14/2012, 11:59 AM
Total Minimum Load Cost July 17, 2004 - March 31, 200905/14/2012, 11:56 AM

Other processes

Resources Electing PIRP Protective Measures12/19/2014, 11:31 AM

Invoicing

Invoicing schedules for monthly and annual CRR auctions

Invoicing Schedule for Jan-Dec 2023 Monthly and 2024 Annual CRR Auctions (Revised)11/06/2023, 8:17 AM
Invoicing Schedule for Jan-Dec 2024 Monthly and 2025 Annual CRR Auctions10/26/2023, 8:12 AM
Invoicing Schedule for Jan-Dec 2022 Monthly and 2023 Annual CRR Auctions (Revised)11/18/2022, 10:09 AM
Invoicing Schedule for Jan-Dec 2021 Monthly and 2022 Annual CRR Auctions11/20/2020, 2:53 PM

View previous invoicing schedules and CRR auctions

Reliability Must Run (RMR)

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

RMR Invoice Template Version 3 (Effective Jun 1, 2013)06/12/2013, 11:04 AM
Prior Period Examples and Guidelines09/03/2002, 1:37 PM

Reliability Must Run (RMR) reporting

RMR Section 5.5 Report Template12/28/2010, 3:08 PM
RMR Section 5.5 Report Procedures12/28/2010, 3:07 PM

Disputes

Submit a settlement dispute form in CIDI*

*For scheduling coordinators only

Settlement Dispute Form09/12/2016, 11:45 AM
Placeholder Dispute Form04/08/2009, 9:33 AM

Retroactive settlements

View previous retroactive settlement documents

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.

California ISO Credit Management Frequently Asked Questions (FAQs)08/03/2023, 10:06 AM
ISO Form Letter of Credit07/20/2023, 8:30 AM
Officer Certification Form02/24/2022, 4:25 PM
Credit Management - Convergence Bidding Estimated Aggregate Liability Components and Data Flow12/23/2020, 9:51 AM
Credit Management - Congestion Revenue Rights Estimated Aggregate Liability Components and Data Flow12/23/2020, 9:51 AM
ISO Unsecured Credit Application02/01/2017, 3:46 PM
ISO Form Guaranty02/02/2011, 1:31 PM

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

ISO Tariff05/18/2024, 7:42 PM
ISO Tariff, Section 11 - California ISO Settlements and Billing01/16/2024, 9:51 AM
Business Practice Manual for Credit Management and Market Clearing05/18/2024, 7:41 PM
Business Practice Manual for Settlements and Billing05/18/2024, 7:41 PM