Third-party verification, inside the platform.
Independent verifiers review your carbon claims in a dedicated workspace, raise findings against the data, and issue a formal opinion — no email chase.
- Global verifiers connected
- Most comments resolved in round one
CarbonSig verification workspace at carbonsig.app. An illustrative steel billet product carbon footprint has completed third-party review. Its three nodes — Iron ore (input, Scope 3), Blast furnace (process) and Steel billet (output, 1.9 kg CO₂e per kg, ISO 14067) — are all reviewed. Zero findings open, one resolved in round two. Verification lifecycle: Self attested, Pending, Under verification, Revisions, and now Verified on CarbonSig.
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How does verification work on CarbonSig?
On CarbonSig, third-party verification happens inside the platform. An independent, accredited verifier gets a read-only Verifier Hub tied to your registered model, raises findings pinned to the exact node, and works round by round to a formal opinion — “Verified on CarbonSig.” CarbonSig hosts the workspace; it does not verify. The verifier is independent.
Verification, chased through consultants and inboxes.
The old way
On CarbonSig
Consultants & inboxes
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Findings scattered across email threads
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Rebuild the model from scratch each round
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An untraceable number you can't defend
One connected platform
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Findings pinned to the exact node
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A locked snapshot per round
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Node-by-node review, claim to opinion
From self-attested to Verified on CarbonSig.
The verifier accepts the engagement
A read-only review environment opens on your registered snapshot.
Findings are raised in context
Each one pinned to its Model → Product → Node path. 5–15 findings in a first review is normal.
You resolve them round by round
Each round is a locked snapshot, so there’s an immutable audit trail from claim to opinion.
The verifier issues a formal opinion
The engagement completes and your products read “Verified on CarbonSig.”
See exactly what a verifier sees — node by node.
The verifier works in a read-only copy of your registered model. Findings are pinned to the exact node. Each round is a locked snapshot. The result is an immutable trail from the first claim to the final opinion — the audit story told once, in order.
CarbonSig verification workspace at carbonsig.app. An illustrative steel billet product carbon footprint is under third-party review — round 2, revisions requested. The system model has five nodes: Iron ore (input, Scope 3, reviewed); Grid electricity (input, Scope 2, reviewed); Blast furnace (process, draft); Direct emissions (Scope 1, draft); and Steel billet (output, reviewed, 1.9 kg CO₂e per kg, ISO 14067). One finding, pinned to Grid electricity, has been resolved in round two: requirement ISO 14067 data quality — the client attached meter data and added a reference. Zero findings open, one resolved. Verification lifecycle: Self attested, Pending verification, Under verification, Revisions requested (current), Verified on CarbonSig. Verification partner: Bureau Veritas. Implementation partner: Kabyax.
In partnership with
Verification partner: Bureau Veritas — co-developer of the verification module.
Implementation partner: Kabyax
Built to the standards your verifier already uses.
ISO 14064-3
Aligned with the standard for verification and validation of GHG assertions; Sankey supports risk-based sampling.
ISO 14067
Aligned with the product carbon footprint standard your claim is calculated to.
GHG Protocol Product Standard
Aligned with the product-level accounting your verifier expects.
A governed workspace for the work you already do.
Accept the engagement
Your own verifier account and a central Engagements workspace; open one for a read-only review environment (Explore · Analyze · Sankey · Bar Chart).
System › Process › Grid electricity
+ FindingReview in context
Raise a Finding and the traceability path (system / process / node) is pre-filled for you; Properties, Requirements and Findings stay in view.
Issue your opinion
Round-based revisions with locked snapshots, through to a formal opinion recorded as “Verified on CarbonSig.”
A person will reply within one business day.
Co-developed with Bureau Veritas.
Bureau Veritas — verification partner; co-developer of the verification module.
“The structured data export eliminated the usual back-and-forth. We could focus on assurance, not archaeology.”
“When a client arrives with a CarbonSig package, we know the evidence is there, organised, and has been through a readiness check.”
A verified number becomes a Carbon Receipt.
When the opinion is issued, your product carries a CAP — a Carbon Attested Product. It’s a live, shareable record, not a static PDF: 628 variables verified in each CAP, 5+ standards mapped per attestation.
CBAM acceptance
A verified number your EU importer can file, instead of a punitive default.
A higher 45V tier
A verified hydrogen carbon intensity drives the credit, up to $3.00/kg.
Green financing & premium markets
Verified low-carbon steel commands 20–30% premiums in Europe (green premium €50–300/t).
What clients ask before verifying.
What does verification cost?
Independent third-party verification runs, as industry estimates: simple $3,000–$8,000, standard $8,000–$18,000, complex $15,000–$35,000, enterprise $30,000–$80,000+. These are estimates — scope, standard and the verifier set the final fee. CarbonSig replaces the consultant, not the verifier, so you don’t pay a consultant $20,000–$60,000+; the independent verifier is billed separately.
Simple
$3,000–$8,000
Standard
$8,000–$18,000
Complex
$15,000–$35,000
Enterprise
$30,000–$80,000+
Industry estimates for the independent verifier’s fees — not a CarbonSig price. Independent verifier required separately. Costs vary by project scope.
How long does it take?
Third-party verification typically takes 8–20 weeks end to end. Roughly: prepare your data 4–12 weeks, select a verifier 1–2, the review itself 2–4, resolve findings 1–3, and the formal statement about 1 week. CarbonSig hosts the review round by round; the independent verifier sets the pace.
Industry estimate; the independent verifier sets the pace. Independent verifier required separately. Costs vary by project scope.
What is a finding?
A finding is a verifier-raised issue in a review round, pinned to a specific node by its Model → Product → Node path, and tracked open → resolved round by round until the verifier issues an opinion. Findings are expected, not failure: 5–15 findings in an initial verification is completely normal.
Can you verify for 45V?
For 45V, you model and register the hydrogen or ammonia carbon intensity (kg CO₂e/kg H₂) and route it through independent third-party verification on-platform — a verifiable pathway. The verified intensity drives the credit tier, up to $3.00/kg. Facilities placed in service after January 2028 no longer qualify. Real example: a US DOE 45V ammonia analysis. See the 45V solution page.
Client or verifier — let's get your numbers verified.
However you verify carbon today, we'll show you the workspace that ends the email chase — for the client raising a number, and the verifier signing off on it.
Independent verifier required separately. Costs vary by project scope.