An ESG director we spoke with recently described her company’s carbon procurement stack in one sentence: “We have a spreadsheet that tells us what we bought, and a prayer that it holds up in an audit.” That sentence is about to become a liability. With the Science Based Targets initiative’s Corporate Net-Zero Standard V2.0 now formally recognizing commodity certificates, book-and-claim chains of custody, and a new category called Ongoing Emissions Responsibility, the flat, undifferentiated ledger most corporate carbon teams rely on is structurally unequipped for what auditors are about to ask. This post is about why a purpose-built book-and-claim carbon credit platform is no longer a nice-to-have for enterprises navigating V2.0, and what it actually takes to engineer one at the data layer, not just the reporting layer. Why SBTi V2.0 Broke the Old Carbon Ledger Model For most of the last decade, corporate carbon procurement tools have treated every credit the same way: an ID, a quantity, a vintage, a status of “retired” or “available.” That model was tolerable when the primary use case was voluntary offsetting against a single, simple claim. It is not tolerable anymore. SBTi’s Corporate Net-Zero Standard V2.0 introduces an implementation hierarchy that requires companies to distinguish between multiple, legally distinct instrument categories operating under different rules simultaneously. Commodity certificates and energy attribute certificates using mass balance or book-and-claim chains of custody are now formally recognized as legitimate implementation tools for certain scope 3 categories, but they are reported separately from the physical emissions inventory and must meet specific integrity criteria around activity matching and double-counting prevention. Separately, the standard introduces Ongoing Emissions Responsibility, a mechanism addressing the years a company continues emitting while working toward its target, which large companies must engage with formally from 2035 or disclose why they haven’t. A book-and-claim carbon credit platform has to hold all of this simultaneously: physical inventory data, decoupled environmental attribute certificates, neutralization-grade removal credits, and OER-eligible instruments, each governed by different eligibility rules, each needing to be queried, filtered, and reported on independently without contaminating the others. Treat these as one undifferentiated pile of “carbon credits,” and a compliance audit will find the gap immediately. The Architecture Problem: Why Linear Ledgers Can’t Model Book-and-Claim Most transaction ledgers, whether in a traditional database or a basic blockchain implementation, are built around a linear delivery model: an asset exists, it moves from party A to party B, and its state changes from “held” to “transferred.” That model works fine for a physical bar of gold or a single share of stock. It breaks down the moment you introduce book-and-claim. Book-and-claim, by definition, separates the environmental attribute of a low-carbon commodity from the physical product it describes. A sustainable aviation fuel certificate, for instance, can be sold, tracked, and retired entirely independently of the physical fuel itself, which may be consumed thousands of miles away by a party with no contractual relationship to the certificate buyer. A linear ledger has nowhere to put that split. It wants one asset, one owner, one location. Book-and-claim wants two parallel records — a physical delivery record and an attribute record that are related but never merged, and that can be independently audited, retired, and reported without either one silently inheriting the other’s status. This is the architecture problem a book-and-claim carbon credit platform actually has to solve: not “how do we record a transfer,” but “how do we record two distinct, cryptographically traceable claims against a single originating event, without ever letting them be double-counted against the same target.” The Software Solution: A Multi-Layered Attribute Schema The fix is not a bigger spreadsheet or a more detailed status field bolted onto an existing table. It’s a fundamentally different data model one where every credit or certificate is described not by a single status flag, but by a structured set of attributes that a query engine can filter against instantly. In practice, this means moving to a schema built around highly structured attribute storage, using an approach like JSON-B fields layered on top of relational tables with dedicated micro-indexes on the fields that compliance teams and auditors will query most often. Rather than a single “credit_status” column, each unit in a book-and-claim carbon credit platform carries a structured attribute object that can include: The engineering value of this approach is that these attributes live at the data layer, indexed and queryable, not buried in a PDF certificate or a manually maintained tag in a spreadsheet. When a compliance officer needs to pull every OER-eligible, Advanced-tier, book-and-claim certificate purchased in a given reporting year, that should be a sub-second, indexed database query, not a week of manual document review before an audit deadline. Read: Why Your Carbon Exchange Needs a Carbon Smart Order Router (Before Your Best Clients Route Around You) Dynamic Tagging: Isolating Permanent Removals From Temporary Reductions One of the more quietly dangerous failure points in legacy carbon ledgers is treating permanence as an afterthought, something noted in a project description rather than something the platform actively enforces. Under V2.0’s durability requirements, this distinction is not cosmetic. A company matching residual emissions against removals needs those removals to carry a storage duration genuinely comparable to the atmospheric lifetime of the emissions being addressed, and the standard proposes either a like-for-like matching approach or a phased transition toward more durable removals through 2050. A book-and-claim carbon credit platform designed for this reality doesn’t just store a “credit type” label. It structurally isolates permanent removal inventory from temporary reduction inventory at the query layer, so that a reporting dashboard, an API call, or an internal override cannot accidentally pull a temporary nature-based credit into a bucket that a company’s climate transition plan has designated for permanent removal matching. This is the same design principle that governs how we’ve approached credit-state architecture on Carbon Plant, our FSA-registered environmental impact exchange: state and category distinctions have to be enforced at the data and settlement layer, not left to a front-end filter that a direct
