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Validation and Verification

The American Carbon Registry (ACR) requires independent third-party validation and verification of all ACR carbon offset projects following the ACR Validation and Verification Standard.

Validation and verification are risk-based processes carried out in conformance with ISO 14064-3:2019 and ISO 14065:2020. ACR validation and verification bodies (VVBs) shall be appropriately accredited for project validation and/or verification in the sector of the applicable methodology, and VVB teams shall meet the competence requirements as set out in ISO 14065 as considered current.

All VVBs for ACR projects must be approved by ACR and be accredited under ISO 14065 by an accreditation body that is a member of the International Accreditation Forum (IAF) and with which ACR has a Memorandum of Understanding (MoU) in place, as detailed in the ACR Validation ad Verification Standard. Verification Bodies for California compliance projects must be accredited by the California Air Resources Board (ARB). 

Information Requirements

ACR-approved VVBs must also execute a Project-Specific Conflict of Interest Form for each project validated and/or reporting period verified.

Validation and verification activities must address all program requirements listed in the American Carbon Registry Standard and follow the requirements of the ACR Validation and Verification StandardProjects must be verified without reservation, with project proponents having addressed all clarifications and corrections required by the VVB.

Once ACR reviews and accepts a Verification Opinion, and the project proponent has completed all other required steps, ACR will post the Verification Report, Verification Opinion, and other documentation to the public ACR website, and issue serialized ERTs to the project proponent’s account.

Validation and Verification Interval

Validation of the GHG Project Plan is required once per crediting period. ACR requires verification at specified intervals in order to issue new ERTs. Validation and the first verification may be conducted simultaneously, and may be conducted by the same approved validation and verification body (VVB).

ERTs may be created and issued annually, or more or less frequently at the Proponent’s request. At each request for issuance of new ERTs, the Project Proponent must submit a Verification Opinion and a Verification Report from an approved VVB based on a desk audit. Projects must also undergo a full site visit verification at an interval no longer than 5 years. Further details are specified in Chapter 9 of the American Carbon Registry Standard, and Chapter 10 of the ACR Validation and Verification Standard.

ACR-Approved Validation and Verification Bodies (VVBs)

Access the list of Validation / Verification Bodies approved by ACR.

Becoming an ACR-Approved Validation/Verification Body

Entities seeking to become an ACR-approved Validation and Verification Body can apply by sending a completed Application for Validation/Verification Body Approval, including the required verifier attestation, and all required attachments to A copy of Sections 1-5 of the application form (no attachments) and a check for the $2500 application fee should be mailed to:

Winrock International
American Carbon Registry VVB Application
204 E 4th St.
North Little Rock, AR 72114 USA

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