CORSIA eligible carbon credits: what airlines can use
CORSIA eligible carbon credits are not just ordinary voluntary offsets. They are emissions units from ICAO-approved programmes, within specific eligibility scopes, that airlines can cancel to meet CORSIA offsetting obligations. This guide explains what makes a credit CORSIA eligible and what buyers
CORSIA eligible carbon credits are not just ordinary voluntary offsets. They are emissions units from ICAO-approved programmes, within specific eligibility scopes, that airlines can cancel to meet CORSIA offsetting obligations. This guide explains what makes a credit CORSIA eligible and what buyers should check before relying on one.
What does CORSIA eligible mean?
A carbon credit is CORSIA eligible only if it is covered by the official ICAO document CORSIA Eligible Emissions Units for the relevant compliance period and scope. It must come from an approved emissions unit programme, meet the approved vintage and activity limits, and satisfy any additional conditions attached to that programme's approval.
This matters because carbon credit eligibility is not decided by an airline, broker, project developer or individual state. ICAO makes eligibility decisions through the ICAO Council, considering recommendations from the Technical Advisory Body.
Eligible emissions units explained
An eligible emissions unit is a unit that an aircraft operator can cancel to meet CORSIA offsetting requirements. The operator's obligation is calculated by the state to which it is attributed. The operator then cancels CORSIA eligible emissions units equal to its final offsetting requirement for the compliance period.
The key word is eligible. A credit may be real, verified and tradable in the voluntary market but still not be eligible for CORSIA. Conversely, CORSIA eligibility does not remove the need for project-level diligence. It is a scheme eligibility filter, not a complete quality guarantee.
How ICAO assesses programmes
ICAO assesses emissions unit programmes against CORSIA Emissions Unit Eligibility Criteria. These include programme design elements and carbon offset credit integrity criteria. The aim is to ensure environmental and social integrity at the programme level.
The Technical Advisory Body reviews programmes and makes recommendations. The ICAO Council then decides which programmes and units are approved. ICAO publishes the outcome in the CORSIA Eligible Emissions Units document, which is updated over time.
Programme eligibility vs project eligibility
One common mistake is to assume that if a programme is listed, every credit from that programme is eligible. That is not how CORSIA works. ICAO approvals often include limitations by vintage, activity type, methodology, country, crediting period or compliance period.
For example, a registry may be approved for the 2024 to 2026 compliance period, but only for certain units and with specific conditions. Buyers need to check both the programme approval and the unit-level details.
| Check | Why it matters | Evidence to request |
|---|---|---|
| Programme approval | Only ICAO-approved programmes can supply eligible units | ICAO eligible emissions units document reference |
| Compliance period | Eligibility is tied to specific CORSIA periods | Confirmation for 2024 to 2026, 2027 to 2029 or relevant period |
| Vintage and scope | Not every issued unit from an approved programme qualifies | Vintage, methodology, project ID, scope limitations |
| Cancellation | Units must be cancelled to meet obligations | Cancellation record for the airline and period |
| Article 6 treatment | International aviation claims raise double-counting risks | Host country authorisation and corresponding adjustment evidence where required |
Article 6 and corresponding adjustments
CORSIA sits in a carbon market shaped by the Paris Agreement. Article 6 is the part of the Paris Agreement dealing with international cooperation and carbon market transfers. A central issue is double counting: the same emissions reduction should not be counted by both the host country and the buyer for separate climate targets.
Corresponding adjustments are accounting adjustments used to avoid that double counting. For CORSIA, this is particularly important because international aviation is using emissions units generated in host countries. Airlines, brokers and project developers increasingly need to understand whether units have the right host-country authorisation and accounting treatment for CORSIA use.
CORSIA eligible vs high quality
CORSIA eligibility and credit quality overlap, but they are not identical. Eligibility asks whether a unit can be used for CORSIA compliance. Quality asks whether the credit is additional, measurable, permanent, independently verified, not double-counted and appropriate for the claim.
An airline can buy a CORSIA eligible unit and still ask deeper quality questions. Is the project avoidance or removal? Is there reversal risk? Are local communities affected? Is the baseline credible? Has the methodology been criticised? Does the unit fit the airline's broader climate strategy?
Buyer checklist for airlines
Start with the ICAO list. Check the latest CORSIA Eligible Emissions Units document, not an old broker deck.
Match the compliance period. A unit eligible for one period may not automatically be eligible for another.
Check scope limitations. Confirm vintage, activity type, methodology, registry and country restrictions.
Ask for registry evidence. The project ID, serial numbers and cancellation record should be traceable.
Check Article 6 documentation. Where required, ask how host country authorisation and corresponding adjustments are handled.
Separate compliance from reputation. A unit can be compliance-eligible but still bring reputational risk if the project quality is weak.
Tool via The Carbon Workbench
Common mistakes
The first mistake is treating "CORSIA eligible" as a generic marketing label. It is a specific compliance status tied to ICAO documents, dates and eligibility limitations.
The second mistake is ignoring vintage and scope. A credit from an approved programme can still fall outside the approved CORSIA scope.
The third mistake is confusing purchase with cancellation. Holding a credit is not the same as cancelling it for compliance.
The fourth mistake is treating eligibility as quality due diligence. Airlines still need project-level risk review, particularly for credits that may attract public scrutiny.
Sources cited
Key takeaway
CORSIA eligibility is specific. Airlines need units from ICAO-approved programmes, within the right compliance period and eligibility scope, with proper cancellation evidence. But eligibility is not the same as full quality assurance. The best buyers check both.