What It Means for SAF, Green Steel, and the Energy Transition
The International Standards Organization (ISO) just published their Book & Claim standard (ISO 22095-3), and it’s a big deal for emerging clean industries. If you’re working in green steel, low-carbon cement, sustainable aviation fuel, or clean hydrogen, here’s what you need to know.
Another Acronym? Meet the TIEC
ISO decided we needed one more term in the alphabet soup: Transferrable Instrument with Entitlement to Claim (TIEC). Yes, we already have Book & Claim Units (BCUs), Environmental Attribute Certificates (EACs), Renewable Energy Credits (RECs), insets, and sector-specific certificates like Sustainable Aviation Fuel Certificates (SAFc). Now add TIEC to your vocabulary. According to ISO, it’s the smallest transferable unit in a Book & Claim system. However, there are important caveats on how these credits can be shared.
Co-Claims Get the Green Light (with Guardrails)
Can multiple organizations claim the same emission-reducing product?The answer is yes if there is no double counting.
The co-claims concept, which was pioneered with SAFc, is already at work in aviation. It’s also gaining traction in other hard-to-abate sectors like shipping, trucking, and steel, and ISO’s standard confirms that it can work.
The standard explicitly allows multiple parties in the same value-chain to share Book & Claim credits when they “perform different roles.” However, those roles need to be better defined. An individual Scope 3 category can have multiple, distinct value-chain operators within it. We can advance a rigorous approach by first establishing uniform mapping for each individual sector, and then by each use case.
Think about aviation: the corporate customer in the seats, the aircraft lessor, the aerospace manufacturer, and the airport each play distinct roles in driving demand and enabling deployment in air travel. Because multiple parties share ownership of overlapping emissions, they should all be able to claim benefits from the same sustainable fuel. Recognizing co-shared mitigation benefits also aligns with how the GHG Protocol assigns responsibility across Scope 1 (direct emissions) and Scope 3 (value-chain emissions) parties.
Deliverability Requirements? There Aren’t Any
This is where ISO draws a clear line in the sand. The defining feature of Book & Claim versus physical chain-of-custody systems, like mass balance, is that environmental attributes transfer separately from physical products. Period.
That means proposals requiring buyers to receive renewable electricity from specific projects, or requiring airlines to physically uplift SAF into their specific aircraft, don’t qualify as true Book & Claim. ISO uses the term “geographic boundaries” as a generic boundary requirement. They define this parameter as either a physical region or a market. Using a sector-wide market as a boundary, for example aviation in its entirety, is viable. Providing flexibility to address different contexts maximizes transport efficiency, creates larger buyer pools, and removes barriers that slow investment in hard-to-abate sectors.
Traders Are In
Here’s a win for commercial reality: traders are allowed.
ISO recognizes that “intermediate TIEC owners can take ownership… without being a producer or supplier, or user.” That means companies can sell excess credits to additional participants in the value chain (remember COVID’s impact on air travel?). Traders aggregate supply, improve pricing, and provide access for smaller players who can’t negotiate directly with producers, all of which helps create market certainty.
The Science Based Targets Initiative (SBTi) should take note. Their sectoral guidance restricting traders, or requiring credits move “down” a supply chain, looks increasingly out of step with ISO’s approach. It may be time for SBTi to revisit that in their upcoming revisions.
Guardrails Still Apply
ISO didn’t create a free-for-all. The standard includes robust safeguards which help build the trust Book & Claim needs to scale:
- Physical connection required: TIECs must link to actual physical goods before transfer
- Documentation and tracking: Every unit needs unique identifiers and must be recorded
- Accurate measurement: Volumes must reflect losses during conversion (e.g., refiners report actual product output, not upstream feedstock inputs)
- Independent recordkeeping: Registries must be free from commercial or regulatory conflicts of interest
- No double counting: Each TIEC can only be retired once, and every transfer must be tracked
- Single retirement for supply chains: If TIECs represent upstream inputs (like wind power for hydrogen), claims can only be retired at the final point
When Can You Start?
ISO designed TIECs to function within what they call a “requirement setter’s system”: basically, sector-specific standard bodies that establish the rules. The Roundtable on Sustainable Biomaterials (RSB) already runs a Book & Claim system for aviation and shipping. Now RSB and others can pursue ISO certification (likely as ISO 22095-3).
Bottom line: Companies can continue mitigating emissions in hard-to-abate industries with confidence that Book & Claim is credible, robust, and ready for prime time, especially when physical supply chains can’t deliver at the pace or scale we need for the energy transition.
