ICAO's global framework to cap net CO₂ emissions from international aviation. Airlines must address emissions growth above a 2019–2020 baseline through Sustainable Aviation Fuel (SAF) and CORSIA Eligible Emission Units (EEUs). Phase 1 (2024–2026) is active with 130 participating states.
CORSIA requires airlines operating international flights between participating states to monitor, report, and address CO₂ emissions growth above a COVID-adjusted baseline (85% of 2019 emissions). It doesn't cap total emissions — it requires airlines to offset growth through two compliance routes.
Route 1: Sustainable Aviation Fuel (SAF) — Use ICAO-eligible SAF to directly reduce lifecycle emissions (typically 60–80% vs. conventional jet fuel). SAF reductions count against your CORSIA obligation, and strategic deployment captures significant incentive value through programmes like US RINs, 45Z, Canada CFR, and EU ReFuelEU.
Route 2: Eligible Emission Units (EEUs) — Purchase carbon credits from ICAO-approved registries (Verra, Gold Standard, ACR, CAR, GCC, ART) to offset remaining emissions. Credits must carry Article 6 corresponding adjustments and host-country Letters of Authorisation (LoAs).
Most airlines use both: SAF where incentive economics work or mandates apply (US routes, EU routes under ReFuelEU), and EEUs for the remainder. The market is structurally short — ICAO projects 980–1,500 million tonnes of cumulative offset demand through 2035, while eligible supply remains extremely limited.
Airlines meet their CORSIA obligation through a blend of SAF deployment and EEU procurement. The optimal mix depends on route network, regional incentives, and mandate requirements.
CORSIA introduces ICAO-level governance with strict eligibility filters, Article 6 integrity requirements, and a phased expansion — creating a structurally short market with rising compliance liabilities.
Credits issued from 2021 onwards must have corresponding adjustments applied under Paris Agreement Article 6, preventing double-counting between airline offsets and host-country NDC claims. Mandatory insurance from empanelled agencies guarantees replacement if CAs fail.
ICAO projects 980–1,500 million tonnes of cumulative demand through 2035, while SAF production remains below 1% of global jet fuel and eligible offsets are restricted to a narrow pool. This persistent imbalance supports durable pricing for CORSIA-qualified credits.
Pilot Phase (2021–23, voluntary) → Phase 1 (2024–26, 130 states) → Phase 2 (2027–35, mandatory for most). Phase 2 shifts to individual allocation, meaning your obligation reflects YOUR growth, not the industry average.
Only 6 ICAO-approved registries. Credits must have crediting periods starting ≥ Jan 2016, vintages 2021–2026, host-country LoAs, and programme-specific exclusions. These filters dramatically reduce the pool of actually eligible supply.
CORSIA overlaps with EU ETS (intra-EU flights), ReFuelEU Aviation (EU SAF mandates), Canada CFR, US RINs/45Z, and provincial programmes. Airlines must navigate dual compliance and optimise SAF deployment across jurisdictions to minimise total cost.
Airlines operating international flights between participating states with aircraft > 5,700 kg MTOW and > 10,000 tCO₂ annually on covered routes. Over 120 countries representing 90%+ of international aviation activity are committed.
Canopy helps airlines and operators calculate CORSIA residual obligations, curate eligible EEUs and SAF credits, manage end-to-end procurement, and build audit-ready reports for ICAO and regulatory compliance.
Calculate CORSIA offsetting requirements by route, phase (Pilot/Phase 1/Phase 2), and growth factor methodology. Quantify EEU demand per compliance period and SAF contribution shortfalls. Benchmark against peer airline fleets.
Discover & shortlist the right instruments. Curated EEUs from 6 ICAO-approved registries (ACR, ART, CAR, GCC, Gold Standard, Verra) ranked by relevance, geography, quality, vintage, and peer alignment. Policy guardrails ensure CORSIA eligibility.
Send RFQs to CORSIA-eligible EEU suppliers and SAF producers. Compare quotes across regions and incentive programmes. Track responses, pricing, and delivery timelines. Manage validity windows and supplier negotiations.
Build optimal EEU + SAF portfolio balancing cost, quality, and compliance risk. AI-generated strategies: High Quality, Removals, Balanced, Cost Effective. Account for route-specific economics and multi-year compliance periods.
End-to-end procurement for EEUs and SAF credits. Spot & multi-year contracting. Track credit delivery, retirement, and ICAO reporting requirements. PO → Invoice → Payment → Delivery → Retirement pipeline.
ICAO-ready compliance reports. Track offsetting obligations by state pair, manage Article 6 corresponding adjustments, and maintain audit-ready inventory of all retired EEUs. Full compliance documentation for regulatory filing.
CORSIA economics vary dramatically by region. US routes deliver the best SAF economics (~$68/tCO₂) with RINs + 45Z stacking. EU routes carry mandatory SAF obligations under ReFuelEU. Canada routes benefit from CFR credit stacking. UAE and APAC face the highest CORSIA exposure with limited SAF infrastructure — EEUs dominate 90%+ of compliance. Climate Decode models the optimal SAF + EEU blend across every jurisdiction your fleet operates in.
Deep-dive analysis on aviation carbon markets, SAF economics, EEU procurement, and airline compliance from our aviation markets team. Series launching soon.
What CORSIA is, who must comply, how it works, and what you need to do now — including a real-world three-year compliance cost model.
Corresponding adjustments, host-country LoAs, empanelled insurance, and why Article 6 labels are non-negotiable for CORSIA compliance.
Route-by-route SAF economics, incentive stacking across US, Canada, and EU, and net abatement cost modelling vs CORSIA EEUs.
Answers to the most common questions about CORSIA, airline compliance obligations, and carbon offset requirements.
CORSIA (Carbon Offsetting and Reduction Scheme for International Aviation) is a global carbon market mechanism developed by ICAO (International Civil Aviation Organization). It requires airlines to offset the growth in their international CO₂ emissions above 2019 baseline levels by purchasing eligible emission units or using sustainable aviation fuel (SAF).
Airlines operating international flights between participating states must comply. Over 130 states are participating. The pilot phase (2021-2026) and first phase (2027-2035) are voluntary, but from 2027 onwards all states with significant international aviation activity are expected to participate in the mandatory phase. Domestic flights and routes to least developed countries are exempt.
EEUs are carbon credits from ICAO-approved programs that airlines can purchase to offset their emissions growth. ICAO has approved several programs including Gold Standard, Verra's VCS, American Carbon Registry, and Article 6.4 mechanism credits. The units must meet strict quality criteria including additionality, permanence, and no double-counting.
Airlines can reduce their CORSIA offsetting requirements by using SAF. The lifecycle emissions reduction from SAF is deducted from the airline's offsetting obligation. This creates a strong incentive for SAF adoption. CORSIA's SAF framework includes sustainability criteria and lifecycle emission calculation methodologies approved by ICAO.
From 2027, CORSIA enters its first mandatory phase (2027-2035). All states representing at least 0.5% of international RTK (Revenue Tonne Kilometres) must participate. This significantly expands coverage beyond the current voluntary pilot phase and creates substantial new demand for eligible emission units and SAF.
Climate Decode's Canopy platform supports airlines and aviation corporates with end-to-end CORSIA compliance: eligible emission unit sourcing and due diligence, SAF pathway analysis, offset portfolio construction, MRV support, and credit retirement. The platform helps aviation clients build optimal compliance strategies that balance cost efficiency with environmental integrity.
Schedule a CORSIA Readiness Assessment with Canopy. Calculate your residual offsetting obligations, curate eligible EEUs and SAF credits, optimise procurement strategy, and build audit-ready compliance reports.