CORSIA FAQ: The Questions Operators and Developers Ask

Monitoring and reporting are mandatory for operators above the threshold from the outset. Offsetting is mandatory on routes between participating States. State participation was voluntary in the pilot and first phases and becomes mandatory for most States from 2027. Operator compliance, once a State participates, has never been voluntary.

No. International flights only. Domestic aviation may be covered by national policy, but not by CORSIA.

More than 10,000 tonnes of CO2 per year from international flights, using aeroplanes above 5,700 kg maximum certificated take-off mass. That is a smaller operation than most people expect — calculate it rather than assuming.

From offsetting, on those routes, yes. From monitoring and reporting, no. Your data feeds the sectoral growth factor that determines everyone else's obligation. Report widely, offset narrowly.

Generally the entity holding the Air Operator Certificate under which the flight is conducted. Wet leases follow the operating certificate, not ownership. Code shares belong to the operating carrier, not the marketing carrier. A group with several certificates has several operators, each tested separately. See scope and thresholds.

No. CORSIA applies to aeroplanes.

It depends on covered emissions, the growth factor, your fuels claim and unit prices — none of which can be answered generically. What can be said: budget from covered emissions rather than total emissions, build a range rather than a point, and model the 2027 step change against your actual network. See the calculation and pricing.

Not responsibly, without knowing project type, vintage, volume, structure and authorisation status. Anyone quoting one without those is not describing something you can actually buy. Voluntary market averages are the wrong benchmark by a wide margin.

Possibly yes. Through 2029 the obligation uses the sectoral growth factor. If the sector grew, you offset that percentage of your own covered emissions even if your own emissions declined. See growth factors.

No. Cancellation discharges the obligation for the period it is reported against. Surplus is simply spent, which is why calculation accuracy has direct financial value.

Participation becomes mandatory for States above defined aviation activity thresholds, expanding covered route pairs substantially. The change is entirely network-specific — model it against your actual routes rather than applying a percentage uplift.

The individual growth factor enters the calculation at 15% weight, rising to 30% from 2033. Faster-growing carriers carry proportionally more.

Almost certainly not. Voluntary credits rarely meet the CORSIA criteria, chiefly because they lack a host-State corresponding adjustment. Buying credits and buying eligible units are different exercises in different markets at different prices.

It must come from an ICAO-approved crediting programme and independently satisfy the Emissions Unit Criteria — additionality, conservative quantification, permanence, verification, no double counting via corresponding adjustment, eligible vintage, no net harm and registry traceability. See the criteria.

No. Programme approval is necessary but never sufficient. Vintage and corresponding adjustment apply at unit level regardless.

It means not eligible. Neither "CORSIA-ready" nor "CORSIA-aligned" nor "eligible pending authorisation" is a standard. All three describe units without host-State authorisation. Buying against them means taking sovereign risk, which can be deliberate but should never be accidental.

The corresponding adjustment requirement. The host government must add the tonnes back into its own national accounting, forgoing them against its own climate target. Many governments decline; many others have no process. This removes the large majority of global credit supply. See corresponding adjustments.

Not by any action of your own. If the issuing programme is approved, the vintage is eligible, and the host State authorises those specific units with a corresponding adjustment, they may become eligible. That is a governmental decision, not a service anyone can sell you.

No. Cancellation discharges the obligation, and the cancellation must then be reported to your national authority. Holding units achieves nothing.

Model the obligation annually and acquire progressively rather than at the deadline. Every operator in the scheme reaches its purchasing decision in the same window at period end, in a market where supply is constrained. Deferral is a bet the whole sector is making simultaneously.

Realistically three to six months if nothing goes wrong: registry account opening four to eight weeks, supply identification two to six weeks, diligence one to three weeks per tranche, contracting two to six weeks, transfer one to three weeks, cancellation and reporting one to two weeks.

Escalate early to your authority and adviser. It is a foreseeable risk, which is precisely why late purchasing is a poor strategy and why contracts should address unavailability.

No. Verification requires independence from the party being verified. Plan for two suppliers from the outset.

Set by national law, not by ICAO, so they vary by State. They have included financial penalties, publication of non-compliance, and in serious cases conditions on operating permissions. Ask your national authority rather than assuming a general answer.

The operator. A consultant can prepare, a verifier can check, an intermediary can source — accountability does not transfer. Someone internally must be able to explain your own data.

It reduces the obligation, it does not remove it — and only when the fuel meets the CORSIA Eligible Fuels criteria, is certified under an approved scheme, and the chain of custody is documented. Burning qualifying fuel without the paperwork produces an environmental benefit and no CORSIA claim.

Increasingly often, and the crossover is moving toward SAF as unit prices rise and growth factors increase. Run the comparison on current numbers — an answer from three years ago is likely stale. See how SAF reduces your requirement.

No. Double claiming across schemes is exactly what verification looks for. Establish which scheme a fuel batch is claimed under before contracting.

No. The project must use a methodology under an ICAO-approved programme, and critically the host State must authorise the units and apply a corresponding adjustment. The second condition eliminates a large proportion of otherwise excellent projects.

Eighteen months to three years from concept to first issuance for a new project, with host-State authorisation the least predictable element. See the supplier pathway.

The host-State authorisation document, programme approval evidence, vintage confirmation, verification report and registry records — in one reply. Project photographs and community narrative sell voluntary credits; they do not answer an airline's question.

Only if India authorises the transfer with a corresponding adjustment. India is developing its domestic Carbon Credit Trading Scheme, and the interaction with Article 6 authorisation is still being worked through. Establish the pathway before committing to a methodology. See CORSIA in India.

No. An operator can face both. Different instruments — credits against allowances — with scopes arranged to limit duplicate obligation on the same emissions. Map your network against both explicitly. See CORSIA vs EU ETS.

No. Different instruments serving different systems.

No. Those units discharge a legal obligation. Claiming them again for a marketing purpose is a double claim of a different kind, and disclosure regulators are increasingly alert to it.

No. ICAO does not certify consultants — no such credential exists. What exists is accreditation for verification bodies and ICAO approval for crediting programmes. Anyone claiming to be "ICAO certified" or "CORSIA certified" is describing something that does not exist, which is a useful screening signal.

Establish scope and threshold position, then get the monitoring plan right before thinking about credits. Errors in the plan compound for years and surface at verification when the year cannot be redone.