CORSIA
Overview
OCP is pursuing CORSIA program eligibility. The requirements set out on this page apply to all Project Developers seeking CORSIA-eligible designation for their OCP credits. CORSIA eligibility is an additional designation on top of standard OCP credit issuance. All standard OCP requirements, including third-party validation and verification, permanence and buffer pool obligations, and no double-counting rules, continue to apply in full.
The Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA) is an emissions mitigation mechanism developed by the International Civil Aviation Organization (ICAO). It requires airline operators to offset CO₂ emissions from international flights that exceed a 2019 baseline by purchasing and cancelling eligible emissions units. As a candidate carbon crediting program under CORSIA, the Open Carbon Protocol maintains specific rules for Carbon Credits that seek to be approved as a CORSIA Eligible Emissions Unit under ICAO's Emissions Unit Eligibility Criteria (EUC).
No Double Claims
In addition to the No Double Counting section of the OCP Handbook, CORSIA-eligible projects must guarantee against Double Claiming. Double Claiming occur when a single emissions reduction or removal outcome is claimed by both the Host Country toward its Nationally Determined Contribution (NDC) under the Paris Agreement, and by an airline operator or other buyer for a separate compliance or voluntary purpose. This section of the Handbook spells out the policies and procedures for obtaining a Corresponding Adjustment from a Host Country and the Project Developer and OCP’s responsibilities to ensure no Double Claiming occurs.
Corresponding Adjustment
A Corresponding Adjustment is the accounting entry made by a Host Country in its national GHG inventory so that the Host Country formally relinquishes its claim to the mitigation outcome. Under Article 6.2 of the Paris Agreement and the ICAO CORSIA Emissions Unit Criteria (EUC) Guidelines, all emissions reductions and removals that occurred on or after 1 January 2021 and that are used toward CORSIA must be accompanied by a Corresponding Adjustment from the relevant Host Country. This is first claimed through a Letter of Authorization from the Host Country and then confirmed in the countries Biennial Transparency Report under Article 13.
Requesting CORSIA-Eligible Designation
To have OCP credits designated as CORSIA-eligible, Project Developers must:
Submit a formal request to the OCP confirming compliance with general and CORSIA-specific requirements in this Handbook.
Identify the Host Country in which the project's emissions reductions or removals were generated, and the relevant vintage year(s).
Obtain and submit a Host Country Letter of Authorization, meeting the requirements set out in the Corresponding Adjustment section above.
Agree on a mechanism to compensate for any double claiming of CORSIA-eligible credits, as described in the Double Claiming section below.
Once OCP has reviewed the request and confirmed it is complete (step 1), the relevant credits will be designated in the registry as pending CORSIA eligible. Full CORSIA eligible designation will be applied once the Letter of Authorization has been received and accepted by OCP (Step 3).
Host Country Letter of Authorization
Before OCP credits can be designated as CORSIA eligible in the registry, the Project Developer must obtain a Letter of Authorization (LoA) from the national focal point of the Host Country. This letter is the formal mechanism through which the Host Country authorizes the use of the credits under CORSIA and commits to applying the required Corresponding Adjustment.
OCP will provide a template LoA to Project Developers upon request. The letter must be completed by the authorized representative of the Host Country and must include:
The official name of the Host Country and the name and title of its authorized representative.
The date of issuance.
The OCP project name and details including the sector, activity type, and crediting period covered.
Confirmation that the Host Country authorizes the credits for use under CORSIA.
Any limits on the number of credits authorized for CORSIA use and any applicable time restrictions.
A formal declaration that the Host Country will not count the mitigation outcome toward its NDC.
A definition of "first transfer" — specifying the point at which the Corresponding Adjustment will be applied (authorization, issuance, or cancellation/retirement of the mitigation outcome).
A commitment that the Corresponding Adjustment will be made in line with the requirements of the Paris Agreement.
A commitment that the Corresponding Adjustment will be reported in the Host Country's Biennial Transparency Reports under Article 13 of the Paris Agreement, and in any subsequent reports required by future CMA decisions.
A commitment that the Host Country will report on granted authorizations and the use of credits for CORSIA in a transparent manner through its Biennial Transparency Reports.
If a project generates credits in more than one country, all relevant Host Countries must each issue a Letter of Authorization covering the credits generated within their jurisdiction.
Registry Functionality for CORSIA-eligible Credits
CORSIA-eligible credits are managed in the OCP Registry with the following additional functionality:
Credits are tagged as CORSIA eligible following successful review of the Host Country's Letter of Authorization. The LoA is published publicly on the registry alongside all other project documentation.
Once credits are transferred for the first time and/or retired, OCP will monitor the relevant Host Country's submissions to the Article 6 database, Biennial Transparency Reports, and any equivalent reports required by future CMA decisions, to obtain evidence that the required Corresponding Adjustment has been made.
The status of the Corresponding Adjustment for each batch of CORSIA eligible credits will be recorded and made publicly available on the OCP Registry.
Retirement records will specify the airline operator for which the credits were cancelled and the date of retirement.
Changes to Host Country Authorizations
OCP monitors the status of Host Country authorizations on an ongoing basis.
If OCP identifies a change in a Host Country authorization, whether through its own reconciliation processes, notification from the Host Country, or notification from the Project Developer, OCP will notify all relevant stakeholders, including the Project Developer, credit holders, the Host Country, the UNFCCC, and ICAO.
If the authorization is expanded (i.e. more credits are authorized than previously), the Project Developer must submit a revised LoA. Upon receipt and review, OCP will designate the additional credits as CORSIA-eligible and notify stakeholders via the registry.
If the authorization is reduced or revoked, OCP will review the affected credits and seek to resolve the discrepancy with the Host Country. If the matter is unresolved within 3 months:
Credits that have not yet been transacted or are still held by the Project Developer will have their CORSIA-eligible designation removed.
Credits that have been transacted but not yet retired will have the designation removed with the agreement of the credit holder. Where no agreement is reached, the credits will be treated as double-claimed and the double-claiming compensation procedure will apply.
Credits that have already been retired will be subject to the double claiming compensation procedure.
Evidence Gathering and Reconciliation
After a Host Country submits its Biennial Transparency Report under Article 13 of the Paris Agreement, OCP will conduct a review to confirm that the required Corresponding Adjustments have been applied.
OCP will identify the specific credits for which the Host Country has applied an Adjustment using the unique serial numbers of the relevant credit batches. Evidence of the Corresponding Adjustment will be published on the OCP Registry alongside the relevant credits. Where a Host Country has not made any claim in the first instance (and therefore no Adjustment is yet required), this will also be recorded on the registry, with monitoring continuing in case a future claim is made.
Double Claiming: Compensation Mechanism
Before approving credits for CORSIA-eligible designation, OCP will require the Project Developer to agree on a binding guarantee to compensate for any double claiming of those credits between airline operators using them under CORSIA and Host Countries counting the same mitigation toward NDC fulfillment.
Binding Guarantee for Project Developers
The Project Developer provides a binding guarantee that any double-claimed credits, those for which the Host Country has not applied a Corresponding Adjustment, will be replaced by an equal volume of CORSIA-eligible credits for the same CORSIA compliance cycle. Replacement credits must be OCP credits or comparable credits approved by OCP, and will be cancelled or used to replace un-retired credits to reconcile the double-claimed mitigation outcome. The guarantee may alternatively commit to full financial compensation to OCP for the cost of procuring equivalent replacement credits.
This guarantee may be provided by a reputable third party, such as an OCP-approved insurance provider. OCP will publish criteria for approved insurance providers. At a minimum, insurers must be regulated by the relevant insurance authority in their jurisdiction and hold a Very Strong rating from Fitch, Standard & Poor's, or an equivalent ratings agency. The insurance product must provide that, in the event of double claiming, the insurer will deliver to OCP either a sufficient number of replacement CORSIA-eligible credits or equivalent financial compensation, at the time of the claim, for OCP to obtain those credits.
Double Claiming: Reconciliation Procedure
If OCP's review of relevant national government reports, following the publication of a Host Country’s Biennial Transparency Report does not show credible evidence that the Host Country has made the required Corresponding Adjustment, OCP will:
Notify the relevant Project Developer and request that they provide evidence from the Host Country that the Adjustment will be made.
If 3 months after the expected declaration of Corresponding Adjustments the Host Country has still not provided satisfactory evidence, OCP will draw on the Project Developer's agreed compensation mechanism to reconcile any double-claimed credits.
Project Developers are responsible for monitoring relevant Host Country reporting and for submitting accurate and timely information on it to OCP.
OCP will independently verify Project Developer submissions and will conduct its own review of Host Country reports to confirm that appropriate Corresponding Adjustments are being made.
Reporting and Annual Disclosure
OCP's Reporting Obligations
On an annual basis, OCP will notify relevant Host Countries, ICAO, and the UNFCCC of all issuances and retirements of CORSIA eligible credits made during that year that may affect claims under NDCs or ICAO guidelines.
OCP's annual report will include the following CORSIA-specific disclosures:
Quantity and serial numbers of credits authorized by Host Countries for CORSIA, broken down by country, vintage, and calendar year.
Quantity of CORSIA-eligible credits retired by airline operators for each CORSIA compliance period.
Corresponding Adjustments confirmed against authorized credits.
Quantity of CORSIA-eligible credits that are active, retired, or cancelled, including serial numbers.
Quantity of CORSIA-eligible credits that were double-claimed and compensated, including quantities and serial numbers.
Reconciliation Against Host Country National Reporting
OCP will conduct a structured reconciliation to compare: (1) the volume of CORSIA-eligible credits OCP has issued, (2) the volume retired by airline operators for CORSIA compliance, and (3) the volume the Host Country has reported as subject to a Corresponding Adjustment in its national reports. This three-way comparison is OCP's primary mechanism for detecting double claiming.
Reports Monitored
OCP will use the Biennial Transparency Report (BTR) to confirm the implementation of agreed up Corresponding Adjustments as well as other reports where necessary.
Review Timing
OCP's annual report will reconcile putstanding Corresponding Adjustments which each country's most recently published BTR. The Annual Report is due by March 31st of the following year.
Double Claiming Reconciliation Procedure
If OCP's review of relevant national government reports, following the publication of a Host Country’s Biennial Transparency Report does not show credible evidence that the Host Country has made the required Corresponding Adjustment, OCP will:
Notify the relevant Project Developer and request that they provide evidence from the Host Country that the Adjustment will be made.
If 3 months after the expected declaration of Corresponding Adjustments the Host Country has still not provided satisfactory evidence, OCP will draw on the Project Developer's agreed compensation mechanism to reconcile any double-claimed credits.
Project Developers are responsible for monitoring relevant Host Country reporting and for submitting accurate and timely information on it to OCP. OCP will independently verify Project Developer submissions and will conduct its own review of Host Country reports to confirm that appropriate Corresponding Adjustments are being made.
Ongoing Compliance
OCP will monitor updates from ICAO and the UNFCCC on the treatment of double claiming and Corresponding Adjustments under the CORSIA mechanism, and will update these Handbook pages and associated procedures as required to maintain compliance with ICAO's evolving requirements and any future decisions of the CMA.
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