The Verifier Hub: a review you can defend.
Accredited third-party verifiers get their own account and workspace inside CarbonSig. The registered model, the requirements and every finding sit in one place — round by round, through to a formal opinion.
The CarbonSig Engagements page at carbonsig.app, illustrative. Three engagements: a steel billet product carbon footprint, status Pending; an ammonia carbon intensity review, status Under review, round 2; and a cement Environmental Product Declaration, status Completed with an opinion issued.
What is the CarbonSig Verifier Hub?
The Verifier Hub is CarbonSig’s workspace for accredited third-party verifiers. A verifier accepts an engagement, reviews the client’s registered snapshot read-only, raises findings pinned to the exact node, works through revision rounds, and issues a formal opinion. A governed, audit-ready environment aligned with ISO 14064-3, ISO 14067 and the GHG Protocol. CarbonSig hosts the review; the verifier is independent.
- ISO 14064-3 — verification and validation of GHG assertions; the Sankey view supports risk-based sampling.
- ISO 14067 — the product carbon footprint standard the claim under review is calculated to.
- GHG Protocol Product Standard — the product-level accounting your requirements library already follows.
Standards and requirements become immutable once referenced in an active engagement, so you — and any accreditation body after you — see exactly the criteria that applied when the engagement opened.
What a verifier does in the Hub.
Six steps, in the platform’s own words. Each one is documented in the help centre.
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Get your verifier account
A verification body has its own account type: an account page for the organisation, a profile for each verifier, and user management to add your team.
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Accept the engagement
An incoming request lands on the Engagements page as Pending. Open it to check the client organisation and the products in scope, select the standards and finding types for the project, then accept and assign it — or decline, which returns the client’s products to their previous status.
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Review the registered snapshot
The engagement opens a read-only review environment on the snapshot the client locked before requesting verification — immutable until a new round begins. Four views (Explore, Analyze, Sankey, Bar Chart) and three persistent panes (Properties, Requirements, Findings). Sankey widths are proportional to emissions, which is where risk-based sampling starts.
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Raise findings against the node
+ Finding pre-fills the traceability path — system, process, node — from wherever you were in the model, so every finding is pinned to the data it questions. The Findings pane is your running record of open and resolved items across the engagement.
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Send a revision request, round by round
With at least one finding raised, Send revision request closes the round: the engagement goes Awaiting response and the client’s model to Revision requested. The client replies per finding and submits; the engagement returns to Under review and the round counter increments. Each round boundary locks a new snapshot, so the audit trail is immutable.
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Issue your opinion
When the review is complete, Issue opinion opens the verification form — one view for a single product, an accordion for several, with a green check on each section once its required fields are done. Complete sets the engagement to Completed and the client’s products to “Verified on CarbonSig.”
What that moves on the client’s side:
The Verifier Hub, article by article.
The help centre carries the screen-by-screen detail, kept current with the platform.
- Getting started as a verifier What the Hub is, how an engagement runs, and where each step is documented.
- Verifier account, profile and user management The verification body’s account, individual profiles, and adding your team.
- Accepting a verification request Review an incoming request, set standards and finding types, then accept or decline.
- Reviewing an engagement The Engagements page, engagement statuses, and the tools inside one engagement.
- Navigating a system during verification The four views, the three panes, and raising a finding against the right node.
- Send a revision request Close a round, hand the findings back, and what changes while you await a response.
- Issuing a verification opinion The opinion form for single and multi-product scopes, and what Complete does.
Run your next engagement on CarbonSig.
Tell us about your accreditation and the standards you verify to, and we’ll set your organisation up with a verifier account.
A person will reply within one business day.