Verification of GHG Emissions Data Reports

This page last modified July 23, 2015

The Regulation for the Mandatory Reporting of Greenhouse Gas Emissions (reporting regulation or MRR) requires the independent verification of greenhouse gas (GHG) emissions data reports.  Verification questions may be sent to  Information about the Offset Verification Program is provided at:

MRR Regulation

Cap-and-Trade Regulation


The reporting regulation was developed under the California Global Warming Solutions Act of 2006 (Statutes of 2006; Chapter 488; Health and Safety Code sections 38500 et seq.) and approved by the California Air Resources Board (ARB or Board) in December 2007, with subsequent amendments in 2010, 2012, 2013, and 2014.  The 2014 MRR revisions became effective on January 1, 2015.  The requirements for independent verification of emissions data reports and ARB oversight of accreditation were included in the original regulation and are consistent with international best practices.  The MRR is codified in Subchapter 10, Article 2, sections 95100 to 95158, title 17, California Code of Regulations.

Information for Verifiers

Questions regarding ARB accreditation and verification should be sent to

Application for Verifier Reaccreditation (an application must be submitted for existing accredited verifiers)

Verification Body Application
Conflict of Interest (COI/NOVS) Form (for 2014 emissions data reported in 2015)
Verification Statement Form (for use with all reporting entities except petroleum refineries)
Petroleum Refinery Verification Statement Form (for use with petroleum refineries only)

Information for Reporting Entities

Reporting entities are required to have their GHG emissions data reports verified each year by an ARB-accredited verification body, beginning in 2010 for 2009 emissions. The third-party verification requirements and deadline are specified in section 95103(f) of the reporting regulation. Compliance dates are summarized at:

Only ARB-accredited verification bodies and verifiers may provide verification services to reporting entities. The following web link provides a list of ARB-accredited verification bodies and additional information:

On April 24, 2013, a webinar titled "Tips for a Successful Verification" was given to emissions data reporters.  A link to the presentation is here.