What Is the Book-and-Claim Model (and How It Works)?

In essence, book-and-claim is a chain-of-custody system that separates the sustainability attributes of a product from its physical flow.

This system is needed because once green molecules enter shared infrastructure, like pipelines or blended fuel tanks, they become indistinguishable. Book-and-Claim solves this by maintaining a verified trail of sustainability data.

Think of Book-and-Claim as a receipt system for environmental benefits. A producer generates a verified low-carbon product, such as SAF or biomethane, and issues a certificate that represents the environmental attributes of that batch. These attributes might include:

• Verified feedstock source

• Renewable content percentage

• Greenhouse gas (GHG) savings

• Carbon intensity (CI) score

• Production method or facility

Here’s how it works in practice, step by step:

1. Production & Certification: A producer generates a batch of sustainable product (for example, 10,000 litres of Sustainable Aviation Fuel made from waste feedstock). This batch is produced under a recognised sustainability standard (such as RSB or ISCC), with its origin, feedstock, and carbon footprint independently certified. The verified data might show, for instance, the feedstock type, renewable content, and the lifecycle greenhouse gas (GHG) savings achieved versus conventional fuel.

   
   

2. Certificate Issued: A certificate (paper or digital) is then issued to represent the environmental attributes of that specific batch. This certificate carries the batch’s key sustainability data – for example, the feedstock origin, the fuel’s carbon intensity, the percentage that is renewable, and the total GHG emission reduction achieved. The certificate is independently verified and entered into a registry or secure database, creating a unique record of that sustainable batch.

   
   

3. Transferred to Buyer: The certificate (often tradable like a credit or token) can be sold or transferred to a buyer, such as an airline, shipping company, or even a corporation, that wants to claim the sustainability benefit of that product. For example, an airline in Region A can purchase the certificate from biofuel produced in Region B, or a company can buy a SAF certificate (SAFc) to cover the emissions from employees’ air travel. The purchaser of the certificates or credits now owns the environmental benefit associated with that batch (like the emissions reduction or renewable content), which they can use toward their sustainability goals or reporting (e.g. Scope 3 emissions reductions). However, the physical batch is sold as conventional product without the sustainability attributes associated with it.

   
   

4. Claim & Retirement: Once the buyer uses the certificate to make a sustainability claim (for example, “we used X litres of SAF worth of emissions reduction”), that certificate is “retired” in the registry. Retiring the certificate means it cannot be claimed again by anyone else. This creates a clear audit trail and prevents any double-counting of the environmental benefit.

   
   
   

A simplified explainer of how the Book-and-Claim model works: Renewable fuel is delivered into the supply network at one location (1), a certificate of its carbon reduction is issued in a registry (2), and a customer elsewhere continues using conventional fuel but claims the green fuel (for example) environmental benefit via the certificate (3). This decoupling lets buyers support green fuel use anywhere while claiming the verified emissions reduction enabled by the purchase (4).