RSB Book & Claim System
Sustainable fuels can achieve 80% GHG emission reductions compared to fossil ones, and if certified against robust and credible standard such as RSB’s sustainability framework, sustainable fuels can also ensure that their production does not negatively affect ecosystems and food security.
With the RSB Book & Claim Programme, RSB is leading the development of a credible and effective book and claim mechanism that aims to expand the outreach of sustainable fuels and accelerate the decarbonisation of hard-to-abate sectors.
RSB’s Book & Claim Programme is designed to align with emerging best practice for credible Scope 3 emissions accounting, including the principles being developed by the Science Based Targets initiative for corporate reporting and the use of commodity certificates. The programme provides assurance that sustainable fuel attributes are robustly governed, transparently transferred, and claimed within the appropriate sector, enabling organisations downstream to make credible in-sector GHG emissions reduction claims from the purchase and use of sustainable fuels.
What is book and claim?
Sustainable fuels are the single biggest opportunity today to decarbonise carbon-intensive sectors such as aviation and shipping.
However, the investments needed to develop sustainable aviation and marine fuels’ technologies, production and supply chains are such that these fuels are only available at limited geographical locations, and at a cost that is still significantly higher than fossil fuels.
This means that it is often out of reach for the growing number of customers globally, which include not only airlines, but also their corporate customers who want to reduce their emissions from business or cargo air travel.
Book and claim offers a solution.
When materials and products move along the supply chain, their attributes – including the sustainability benefits – are tracked, documented and verified via the ‘chain of custody’.
Book and claim is a chain-of-custody model, “in which the administrative record flow does not necessarily connect to the physical flow of material or product throughout the supply chain” (Source: ISO 22095:2020). It allows a customer to de-couple specific attributes from the physical product – like its sustainability benefits – and transfer them separately via a dedicated registry. This approach, which has been successfully implemented in the renewable electricity sector, is particularly valuable for sectors like aviation and shipping which require versatile chain of custody models to link supply with growing global demand.
Book and claim does not require the buyer and the seller to be connected with a physical supply chain, as is the case for other chain-of-custody model such as mass balance. And while a customer may not technically fly or ship their goods on sustainable fuels, their purchase demonstrates market demand and supports the development of supply globally. In turn, they may claim the sustainability benefits, such as the greenhouse gas emission reduction, towards their voluntary targets.
RSB Book & Claim System
The RSB Book & Claim System has been created to monitor and manage the complex – but necessary – approach to scaling the supply of sustainable fuels in hard-to-abate sectors.
The RSB Book & Claim System includes the RSB Book & Claim Manual (normative procedure), the RSB Registry (digital data storage system) and the RSB Book & Claim Recognition Procedure (normative procedure for a registry ecosystem).
RSB is perfectly positioned to lead in the development of book and claim. Building on our best-in-class sustainability framework, which has been recognised by EU RED and CORSIA, our work has consistently prioritised sustainability and decarbonisation.
RSB Book & Claim Manual
The RSB Book & Claim Manual sets out the requirements for registering, transferring and retiring the sustainability attributes of sustainable aviation fuels, including the greenhouse gas emission reduction benefit, in the form of a Book & Claim Unit. It includes aspects related to sustainability certification, sustainability data points, claims, double counting and additionality.
An initial draft of government policies categorised according to the additionality categories defined in the RSB Book and Claim Manual is available here. Updates to the RSB Registry to implement the changes introduced in Version 4.2 will take place in January/February 2026, and we will communicate these updates through the RSB Registry newsletter and at upcoming events.
The Manual has been developed, and will be regularly updated, through a process including genuine multi-stakeholder consultations, expert analyses, and pilots.
RSB Book & Claim Registry
The RSB Book & Claim Registry is a multi-role digital application accommodating a robust process for decoupling sustainability attributes from certified renewable fuels. The decoupled sustainability attributes can be used to issue a Book & Claim Unit (BCU), which can be securely transferred to another account holder who wishes to claim them. As such, the RSB Registry provides a secure and credible space for companies to participate in book and claim and benefit from lessons learned.
RSB uses its experience from operating the RSB Registry to approach an ecosystem harmonisation and collaboration, which will ultimately shape the RSB Book & Claim Recognition Procedure, a normative book and claim basis for other registry operators.
RSB Book & Claim Recognition Procedure
The RSB Book & Claim Recognition Procedure, , promotes an ecosystem approach to the growing market of independent registries. In doing so, this will provide the market with a robust and credible framework that can be used by any independent book and claim initiative to build trust and market acceptance.
This robust and transparent approach ensures that an operator’s registry meets technical and chain-of-custody related requirements driving reliable sustainability impacts, and describes compliance with the latest RSB Book & Claim Manual and technical components.
Book & Claim Pilots
RSB has been working to pilot the requirements of the RSB Book & Claim Manual in the aviation sector with several partners including, in alphabetical order, Airbus, Airbp, Etihad, JetBlue, Microsoft, the Sustainable Aviation Buyer’s Alliance (SABA), Singapore Airlines, TotalEnergies, World Energy and United Airlines – as well as 4Air and Shell Aviation for the registry recognition framework component.
We are currently designing additional pilots to test new use cases in the aviation, and expand the RSB Book & Claim System’s scope to the maritime sector.
Book and Claim Community
RSB co-leads the Secretariat of the Book and Claim Community, a global initiative working to align and strengthen book and claim systems that enable credible decarbonisation across hard-to-abate sectors. The Community provides a collaborative space for organisations to share knowledge, shape best practices and support the development of effective, interoperable systems that can scale with integrity.
This work is delivered in partnership with Smart Freight Centre, and both organisations co-lead the Secretariat to support coordination, governance, and implementation.
RSB Book & Claim Platform
The RSB Book & Claim Platform is a series of meetings where the RSB members have their say in the development of the RSB Book & Claim System and share knowledge and best practice.
The RSB Book & Claim Platform is for RSB members only.
ISEAL Interoperability Project Results
As part of our commitment to building credible, transparent and connected Book and Claim systems, RSB has led an interoperability research project funded by the ISEAL Innovations Fund with support from the Swiss State Secretariat for Economic Affairs (SECO). The project examined how Book and Claim registries can coordinate more effectively by developing shared governance principles, a harmonised data model and a technical API specification that together form the basis for future registry collaboration across the sustainable aviation fuel (SAF) ecosystem.
The project resulted in several key outputs, including a governance and ecosystem characteristics framework, a harmonised data book and a complete API specification designed to support secure and consistent data exchange. These outputs provide a strong foundation for future testing and development with registry partners.
RSB Academy's e-learning course
If you’re looking to learn more about book and claim, take a look at the RSB Academy’s online course on Chain of Custody.
This course will provide you and your organisation with the insight and understanding of Chain of Custody systems, covering the mass balance and book and claim approaches, especially in the context of the RSB Book & Claim System.
Relevant news
RSB and World Energy launch ‘Demand Signal Recognition Book and Claim Pilot’ to boost sustainable aviation fuel market
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RSB introduces Book & Claim Registry tool to drive sustainable decarbonisation in the transport sector
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