The Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA) has come into effect.
Airlines operating on covered routes must build strategies and plan their budget to remain compliant with the scheme.
To do this, operators must either reduce their CO2 emissions or purchase CORSIA Eligible Emissions Units (CEEUs) to offset them.
However, the International Civil Aviation Organization (ICAO) has introduced another way for airlines to reduce their emissions and their offsetting threshold.
Through the introduction of what it calls CORSIA Eligible Fuels (CEFs), the scheme now allows airlines to abate their CO2 emissions at source, reducing the amount of emissions they produce and the number of CEEUs they would have to purchase to offset them.
In practice, fuels that meet the CEFs criteria come in two distinct categories.
CORSIA sustainable aviation fuels (renewable or waste-derived fuels).
CORSIA lower carbon aviation fuels (fossil-based fuels that still meet sustainability criteria).
These fuel types are mutually exclusive options.
It’s quite possible for airlines to use both types of fuels to abate their emissions.
However, determining which fuel will work best, whether a fuel based on renewables, or a lower emission fossil-based fuel, will require an in-depth analysis.
We work with airlines to analyse both compliance pathways - offsetting and fuel use - to build a strategy that responds to your specific routes, fleet, and budget constraints.
To see how we can help you access CEFs, or CEEUs, contact our carbon team, here.
Although eligible fuels are a proven way of reducing emissions, their use involves a number of practical challenges, which this section will address.
Supply and cost are the biggest hurdles in accessing CEFs.
Finding a consistent supply of eligible sustainable aviation fuels can be difficult, due to feedstock availability and production capacity, while CEFs can often be more expensive compared to conventional jet fuel.
However, since CEFs function as a substitute for EEUs to some extent, their pricing should bear some relation to the price of carbon credits. Nonetheless, this relationship isn’t necessarily straightforward: prices can be affected by supply and demand on both sides.
Whether it makes financial sense to invest in CEFs, or purchase CEEUs will depend on a variety of market factors that will require expert analysis.
To be certified, SAFs must meet specific sustainability criteria.
However, meeting ICAO's sustainability criteria isn't straightforward. The entire production process - from feedstock production or collection right through to blending - will need to be assessed.
In addition, only Sustainability Certification Schemes (SCS) that have been approved by the ICAO Council can certify fuel producers, and those schemes themselves must satisfy stringent criteria before they're recognised.
The certification ensures sustainability through each key stage of production, including the sustainability of feedstock cultivation, traceability of sustainable materials, and the verified reduction of lifecycle emissions.
(to see which fuel batches and economic operators are already certified, ICAO maintains information on CORSIA certified fuels on their website, see here).
The regulatory complexity of CEFs also creates barriers to uptake. In practice, it’s not possible to simply buy sustainable fuels and achieve compliance.
It’s essential to understand the fuel's actual lifecycle emissions reduction value, and that can only be done by calculating their carbon intensity.
This calculation determines exactly how much the fuel will contribute to your CORSIA compliance.
However, in practice, this calculation can use default values accepted by CORSIA, or the actual lifecycle emissions as verified by an approved SCS using CORSIA's methodology, easing some of the complexity for this stage of the process.
Not all sustainable aviation fuels qualify for CORSIA. For a fuel to be 'eligible', it must meet strict ICAO requirements.
The main requirement is that a CEF must deliver a minimum 10% lifecycle greenhouse gas reduction compared to conventional jet fuel. Producers in turn, must ensure high standards of sustainability, including sustainable use of land, water resources, and food security.
This includes the production and use of feedstocks.
Under CORSIA, feedstocks are broadly categorised into five types:
These are crops grown specifically for fuel production.
Examples include virgin oils extracted as the main product from oilseed processing.
These are products generated alongside primary products, also with economic value, such as molasses from sugar refining.
These are secondary products with inelastic supply but economic value, including glycerine from biodiesel production.
These are materials with fixed availability, that are not produced on demand, such as used cooking oil or tallow.
These are secondary materials that, as with waste, are not produced on demands, such as wheat straw or corn stover.
The classification affects how the fuel's lifecycle emissions are calculated and whether certain emission factors can be set to zero.
CFP Energy works with biofuel distributors across Europe, supporting the long-term decarbonisation of major corporate operators across multiple industries.
To learn more about our biofuel supply capabilities get in touch with our team from this dedicated page.
For airlines, CORSIA Eligible Fuels offer far more than a compliance mechanism—they are a direct investment in real-world decarbonisation.
Unlike offsets, which compensate for emissions already released, CEFs reduce emissions at source and provide a more tangible sustainability story for customers, regulators, and investors.
This makes them strategically valuable for airlines seeking to demonstrate leadership in climate action.
Proactively securing a supply of CEFs can also stabilise long-term compliance costs. As demand rises and ICAO ramps up climate obligations, the price of EEUs is expected to become increasingly volatile.
Locking in eligible fuel supply early can therefore protect operators from future cost spikes while giving them a clear, credible pathway to long-term emissions reduction.
In a regulatory landscape where scrutiny of carbon claims is intensifying, airlines that commit to eligible fuels can differentiate themselves, strengthen brand reputation, and show meaningful progress toward net-zero aviation.
This proactive approach directly supports CORSIA’s broader effectiveness. By reducing lifecycle emissions at source, CEFs help lower global aviation emissions rather than simply shifting carbon obligations elsewhere.
Airlines that invest early position themselves not just as compliant operators, but as frontrunners in sustainable aviation.
CFP Energy supports airlines at every stage of their eligible fuels journey, helping you understand the regulatory landscape, access supply pathways, and evaluate the true compliance value of each fuel option.
Our team combines deep expertise in renewable fuels, ICAO sustainability rules, and lifecycle emissions modelling to guide operators through the complexities of the CORSIA framework.
We help airlines assess and compare different CEFs, calculate their precise lifecycle emissions reductions, and understand how each batch will affect offsetting requirements and overall compliance cost.
Beyond analysis, we support procurement strategy, risk assessment, and reporting obligations—ensuring that every fuel decision is robust, verifiable, and cost-effective.
With strong market intelligence and access to suppliers across Europe and beyond, CFP Energy provides airlines with the data, insights, and commercial pathways needed to navigate a fragmented and rapidly evolving renewable fuels market.
Our aim is simple: to give operators clarity, confidence, and strategic advantage as they transition toward lower-carbon operations under CORSIA.
Get your strategy in place by contacting our team, here.