Book-and-claim explained: How it works and why it matters

Published in 2026

Book-and-claim mechanisms are based on a simple idea: separating the environmental attribute of a renewable product from its physical delivery. In the case of Sustainable Aviation Fuel (SAF), this means that customers pay for the verified climate benefit of SAF while the physical fuel is produced and used where it makes the most sense.
SAF is widely seen as the most important lever to defossilize air travel in the coming decades. Yet scaling SAF is a complex challenge that requires coordinated progress in production, infrastructure, and financing. SAF is moving from demonstration projects to commercial reality. Book-and-claim offers a practical way to overcome early infrastructure hurdles and give investors confidence. It is a crucial tool to accelerate the transition from fossil to renewable fuels.

Decoupling logistics from climate impact

Green electricity certificates are a familiar example of book and claim in practice. Consumers may not receive renewable power directly from their socket, but they purchase certificates that guarantee the same amount of clean energy they bought was produced and fed into the grid.
The same logic applies to SAF. The fuel can be produced where it’s most efficient and used where it’s most practical, while the emissions reduction is “claimed” by a buyer anywhere in the world.
“Book-and-claim turns SAF from a local product into a global climate instrument,” says Dr. Christoph Falter, Head of Strategy at Synhelion. “It allows SAF producers to operate efficiently and buyers to act immediately, without being limited by local availability.”

Why aviation needs it now

Today, SAF is available at only a limited number of large airports, and most airports don’t supply SAF yet. That means even willing buyers – airlines or corporate travelers – often can’t access it locally. The result is inefficiency: fuel reaches only a few connected airports, while demand in other regions cannot be met. Producers struggle to secure long-term offtake contracts, slowing down new investments and scaling of SAF technologies.
Book-and-claim breaks this cycle. By separating the physical molecule from the environmental attribute, it enables a global market where SAF produced in one location can be “claimed” by buyers anywhere. This unlocks demand, strengthens offtake signals, and accelerates new capacity. In practice, that means buyers can credibly account for SAF use even if their local airport cannot supply SAF yet.

Ensuring credibility and trust

The system’s credibility relies on transparent governance. Each batch of SAF is verified by an independent third party, then assigned a unique digital certificate that records where and how it was produced, its quantity, and lifecycle emissions.
Registries track these certificates until they are retired (i.e., permanently removed from circulation to prevent resale or double counting), ensuring that every carbon reduction is claimed only once. Interoperable registries and clear transfer rules safeguard the system’s integrity.
“Blockchain can help as a tamper-resistant ledger, but it’s not the silver bullet,” says Falter. “Good governance, competent audits, and modern, API-based registries are what really ensure integrity.”
For customers, clarity is key. Each certificate should be traceable to a real batch of fuel, and any public claims, such as statements about SAF use or emissions reduction, should be simple and verifiable. Transparency builds confidence and trust across the value chain.

From accounting tool to market catalyst

Beyond transparency, book-and-claim creates powerful economic incentives. By opening access to a global pool of buyers, producers can finance and operate SAF plants with greater confidence.
Decoupling the environmental attribute from physical fuel delivery multiplies the addressable market, reduces risk, and attracts investment. “When global demand channels are opened, production is de-risked and new plants can secure financing faster,” Falter notes.
As trading of verified certificates grows and market liquidity improves, price signals become more reliable. Over time, this supports larger production volumes, which helps bring down the cost of physical SAF. As a result, the price gap between physical SAF and book-and-claim certificates can narrow, since greater scale and lower risk make producing SAF more affordable.

Why it fits Synhelion’s renewable fuels

Synhelion’s fuels are made from renewable energy, ideally in locations where renewable resources are abundant. For example, with a plant in Morocco, SAF could be produced and supplied locally. Customers worldwide can then buy and retire matching certificates within the same reporting period, each linked to verified lifecycle data.
“This allows us to produce SAF where it is most efficient and still deliver a certified, audit-ready climate benefit to any customer worldwide,” Falter explains. “Book-and-claim connects renewable production sites to a global aviation market.”

The current status of book-and-claim

Today, there is not yet a universally recognized, cross border book and claim mechanism.
Around the world, book-and-claim systems for Sustainable Aviation Fuel are beginning to take shape but have not yet reached global maturity. The Roundtable on Sustainable Biomaterials (RSB) has launched a pilot framework, and initiatives such as Airbus’s SAF certificate program and the first Latin American book-and-claim deal by GOL Linhas Aéreas and Vibra Energia show growing momentum. IATA has launched its SAF registry in 2025, which connects SAF producers with airlines and enables claiming environmental benefits without physical access to the fuel. In Europe, the ReFuelEU Aviation regulation foresees the creation of a harmonized registry to enable cross-border certificate trading. However, a universally recognized system is still under development, with key issues like registry governance and double-counting safeguards being refined.

What’s needed next

For book-and-claim to scale across borders, policy and accounting systems need to catch up. Three steps are most urgent:

1. Interoperable registries with mutual recognition and no duplicate issuance.
2. Aligned accounting rules that define how SAF certificates count toward quotas and emissions inventories, avoiding double claims between airlines and travelers.
3. Consistent claim standards with harmonized data fields and disclosure formats worldwide.

“The technologies to produce renewable fuels are ready,” says Falter. “Now the world needs harmonized governance and policy recognition to make it work globally.”

The bigger picture

Aviation is the ideal starting point: it has a concentrated fuel market and faces strong regulatory pressure to defossilize. Once the model is proven, the same registry architecture could extend to shipping and, eventually, road transportation through mass-balance systems.
Synhelion’s view is clear: aviation should lead the way – but the book-and-claim framework could be cross-sector by design, with common standards and safeguards to prevent double counting.

Conclusion – building the backbone for net-zero flight

Book-and-claim is more than an accounting mechanism. It’s the backbone that can connect global SAF supply and demand, unlock investment, and deliver verified climate impact at scale.
With credible governance, transparency, and aligned policy, it can turn today’s fragmented SAF market into a coordinated system that finally allows aviation to fly net zero.
“Although the SAF is used in another location, the climate benefit remains global, as CO₂ reductions are not tied to geography,” explains Falter. “The system allows demand to develop before infrastructure is in place, channeling investment into new SAF plants.”

How book-and-claim works in practice

1. SAF is produced: A producer produces Sustainable Aviation Fuel (SAF), which is then blended with fossil jet fuel at a refinery and supplied to an airport for use in departing aircraft.

2. Emission reductions are “booked”: The environmental attributes are recorded in a digital registry – each unit of SAF gets a unique certificate.

3. A buyer “claims” the benefits: A company or traveler who cannot directly access SAF can purchase these certificates to account for their air travel emissions. By doing so, they support SAF production and are entitled to claim the corresponding CO₂ reduction in their sustainability reporting under Scope 3 emissions.

4. Chain of custody is maintained: The registry ensures traceability and prevents double counting. Each certificate has a unique ID. Once a buyer redeems it, it’s retired from the system. Auditors can verify that each liter of SAF is only claimed once.

Find out more about our renewable synthetic fuels and subscribe to our newsletter to follow us on our path to clean, sustainable transportation.