Biochar has become one of the most sought-after durable removal categories in the voluntary carbon market, which means buyers now see a wide range of offers of very different quality. Because biochar is a removal rather than an avoidance credit, the diligence questions are specific — and getting them right protects both the climate claim and the reputational risk of the purchase.
Why biochar due diligence looks different
Avoidance credits ask whether an emission was prevented. Biochar, like other removals, asks a more demanding question: is the carbon that has been pulled from active circulation genuinely going to stay locked away for the durability period claimed? That question is answerable — biochar's permanence is physically measurable, unlike many modelled climate claims — but only if the underlying evidence is actually requested and reviewed.
The four-lens framework
1. Additionality
Would the biochar project have happened without carbon finance? Look for a documented baseline and barrier analysis — financial, technological or regulatory barriers the project overcomes — rather than a bare assertion. Projects converting genuinely surplus, otherwise-burned or discarded biomass into biochar have a more straightforward additionality story than projects using biomass that already had a productive use.
2. Permanence
This is the question that defines a removal. Request H:Corg (organic) lab results from an accredited laboratory, alongside the sampling plan showing how many samples were taken, how often, and across which production batches. A single favourable sample is not evidence of consistent quality — batch-to-batch variability is exactly what a good sampling plan is designed to catch.
3. MRV quality
Ask how measurement, reporting and verification actually work in practice: is monitoring conservative and audit-ready, is there any digital MRV (dMRV) component, and can you see the raw data behind headline figures — not just a certificate. Weak or thin MRV data is one of the more common ways credit quality quietly erodes.
4. Delivery risk
Especially relevant for forward offtakes: does the developer have a track record of delivering committed volumes on schedule? What happens contractually if production falls short? A project with strong integrity fundamentals but no delivery history still carries execution risk that should be priced into the deal.
| Quality pillar | What to request | Why it matters |
|---|---|---|
| Additionality | Documented baseline & barrier analysis | Confirms carbon finance was needed for the project to happen |
| Permanence | H:Corg (organic) lab results + sampling plan | Evidences how long the carbon is estimated to stay locked away |
| MRV quality | Raw monitoring data, VVB verification reports | Shows whether the numbers are defensible, not just asserted |
| Delivery risk | Delivery track record, contractual remedies | Determines whether committed volumes will actually arrive |
The document checklist
Before purchasing, a reasonably thorough diligence pass should include:
- The project design document and the specific methodology used (Verra VM0044, Puro.earth, Isometric or another registered pathway).
- The baseline and barrier analysis supporting additionality.
- H:Corg (organic) lab reports and the underlying sampling plan.
- Verification body (VVB) reports from the validation and verification process.
- Registry issuance records, confirming credits were actually issued, not just claimed.
- CCP label status, where applicable — as of 2026, ICVCM has approved three biochar methodologies against its Core Carbon Principles.
- For offtakes, the delivery schedule and any prior delivery track record.
Red flags worth pausing on
Spot purchases vs forward offtakes
The diligence emphasis shifts depending on deal structure. Spot purchases of already-issued credits let you review actual, historical MRV and verification records — the evidence already exists. Forward offtakes, agreed before or early in a project's life, carry more delivery risk and less finished evidence, so diligence leans more heavily on developer track record, contractual delivery terms, and interim reporting commitments.
The bottom line
Biochar's core appeal — physically measurable permanence — is also what makes rigorous diligence achievable, not just advisable. Buyers who request the underlying evidence, rather than accepting summary claims, are far better positioned to defend their purchase decisions to auditors, stakeholders and their own leadership.
If you are evaluating a biochar offer and want an independent second opinion, our due-diligence advisory works specifically with corporate buyers on additionality, permanence, MRV and delivery risk. Get in touch before you commit.
This checklist reflects general due-diligence practice as of August 2026 and is not exhaustive or a substitute for independent legal, financial or technical advice. Methodology and registry rules evolve — verify current requirements before relying on any specific detail.