Myth-busting Voluntary carbon market integrity (ICVCM, VCMI): separating hype from reality

The voluntary carbon market (VCM) traded approximately $1.7 billion in credits during 2025, down from $2.1 billion in 2023 but stabilising after two years of turbulence triggered by investigative reporting, academic scrutiny, and institutional hand-wringing. Into this credibility vacuum stepped two governance bodies: the Integrity Council for the Voluntary Carbon Market (ICVCM), which sets supply-side quality standards through its Core Carbon Principles (CCPs), and the Voluntary Carbon Markets Integrity Initiative (VCMI), which governs demand-side claims through its Claims Code of Practice. Together they represent the most ambitious attempt to professionalise a market long plagued by opacity, inconsistent quality, and justified scepticism. Yet persistent misconceptions about what these frameworks actually do, how they interact, and whether they can deliver on their promises continue to distort corporate procurement decisions, investor allocations, and policy design across the UK and globally.

Why It Matters

For UK-based founders and corporate sustainability leads, the VCM sits at an awkward intersection of regulatory expectation and reputational risk. The UK's Transition Plan Taskforce guidance, finalised in late 2024, explicitly references high-integrity carbon credits as a legitimate component of corporate transition plans, provided they meet robust quality criteria. The Financial Conduct Authority's anti-greenwashing rules, effective from May 2024, require that any environmental claims, including those based on carbon credit purchases, be fair, clear, and not misleading. Meanwhile, the UK Advertising Standards Authority has increasingly scrutinised "carbon neutral" and "net zero" claims, ruling against several brands in 2024 and 2025 for inadequately substantiated offset-based assertions.

The commercial implications are substantial. UK companies collectively purchased an estimated 45 million tonnes of carbon credits in 2025, with an average price of $12.40 per tonne for standard avoidance credits and $142 per tonne for engineered removal credits. Getting procurement wrong means either overpaying for credits that deliver no real climate benefit, or exposing the organisation to greenwashing litigation and reputational damage. The ICVCM and VCMI frameworks are designed to resolve this tension, but only if buyers understand what these standards actually guarantee and what falls outside their scope.

The Science Based Targets initiative (SBTi) further complicated the landscape in 2024 when it released revised guidance permitting limited use of Environmental Attribute Certificates, including carbon credits, for Scope 3 abatement. This policy shift made the integrity question even more commercially relevant, as credits meeting CCP standards could potentially count toward validated science-based targets for the first time at scale.

Key Concepts

Core Carbon Principles (CCPs) are the ICVCM's ten assessment criteria that carbon credits must satisfy to receive a CCP label. These criteria span additionality (the project would not have occurred without carbon finance), permanence (the emission reduction or removal endures for at least 100 years for removal credits), robust quantification (conservative baselines and monitoring), and sustainable development safeguards (no harm to local communities or ecosystems). The CCP assessment process evaluates entire crediting methodologies and programme-level governance, not individual projects, before applying project-level screening.

Claims Code of Practice is VCMI's framework governing how companies can make public claims about their carbon credit use. It establishes three tiers: Silver (company has a validated science-based target and has retired high-quality credits covering at least 20% of remaining unabated Scope 3 emissions), Gold (at least 60% coverage), and Platinum (at least 100% coverage). Crucially, the Claims Code requires companies to demonstrate they are actively decarbonising their value chains before making any credit-based claims, preventing credits from substituting for direct emission reductions.

Corresponding Adjustments refer to the Article 6 mechanism under the Paris Agreement, whereby the host country of a carbon project adjusts its national emissions inventory to avoid double counting when credits are used by buyers in other jurisdictions. Whether VCM credits require corresponding adjustments remains one of the most contentious governance questions, with ICVCM initially deferring the requirement but facing pressure from the EU and several national regulators to mandate it.

Additionality Testing evaluates whether a project's emission reductions would have happened without carbon credit revenue. Traditional additionality tests use investment analysis (is the project financially viable without credit income?) and barrier analysis (do non-financial barriers prevent the project without carbon finance?). Newer approaches include activity-penetration tests, which assess whether the project type has achieved commercial viability in the host jurisdiction, and dynamic baselines that adjust as market conditions evolve.

VCM Integrity KPIs: Benchmark Ranges

Metric	Below Average	Average	Above Average	Top Quartile
Credit price (avoidance, per tCO2e)	<$4	$4-12	$12-25	>$25
Credit price (removal, per tCO2e)	<$30	$30-80	$80-200	>$200
Buffer pool allocation (%)	<10%	10-15%	15-25%	>25%
Third-party verification frequency	None	Every 5 years	Every 2-3 years	Annual
Buyer due diligence spend (% of credit cost)	<2%	2-5%	5-10%	>10%
SDG co-benefit documentation	None	Self-reported	Third-party assessed	Impact-verified
Claim substantiation lead time	>12 months	6-12 months	3-6 months	<3 months

What's Working

CCP Label Driving Market Segmentation

By early 2026, the ICVCM had completed assessment of 14 crediting methodologies across four major programmes (Verra, Gold Standard, American Carbon Registry, and Climate Action Reserve), with eight methodologies receiving CCP-eligible status. This created a clear two-tier market. CCP-labelled credits traded at a 35-55% premium over unlabelled credits from the same project categories, signalling that buyers are willing to pay for verified integrity. Major corporate procurement programmes at companies including Microsoft, Salesforce, and Unilever publicly committed to purchasing only CCP-labelled credits from 2026 onward, creating demand-side momentum that accelerates methodology assessment timelines.

VCMI Claims Code Reducing Greenwashing Risk

Approximately 60 companies globally adopted the VCMI Claims Code by the end of 2025, including several FTSE 100 firms. These early adopters report that the Claims Code's requirement for a validated science-based target before making credit-based claims effectively filters out companies attempting to use offsets as a substitute for decarbonisation. The tiered structure (Silver, Gold, Platinum) provides flexibility that binary "carbon neutral" labels lacked, allowing companies at different stages of their decarbonisation journey to make proportionate, defensible claims. UK-based retailer Marks and Spencer adopted the Silver tier in 2025, citing the Claims Code's alignment with FCA anti-greenwashing requirements as a primary motivation.

Registry Programme-Level Assessment

The ICVCM's decision to assess crediting programmes at the governance level, not just individual methodologies, strengthened systemic quality. Programmes must demonstrate adequate conflict-of-interest management, transparent stakeholder consultation processes, and robust registry infrastructure. This programme-level scrutiny prompted Verra to accelerate governance reforms it had announced in 2023, including establishing an independent standards board and implementing enhanced conflict-of-interest policies.

What's Not Working

Assessment Timelines Creating Market Uncertainty

The ICVCM's methodology assessment process has proven slower than anticipated, with only 14 methodologies assessed by early 2026 against an original target of 40+. This bottleneck means that the majority of VCM transactions still involve credits without CCP labels, perpetuating the quality ambiguity the framework was designed to resolve. Delayed assessments particularly affect nature-based solutions methodologies (REDD+, afforestation, mangrove restoration) where additionality and permanence questions are most complex, precisely the categories where integrity concerns are most acute.

Corresponding Adjustment Deadlock

The question of whether VCM credits require host-country corresponding adjustments remains unresolved. Without corresponding adjustments, there is a theoretical risk that both the buyer and the host country claim the same emission reduction. ICVCM initially categorised credits as CCP-eligible with or without corresponding adjustments, using disclosure rather than mandating adjustments. This approach satisfies neither those demanding rigorous accounting (including several EU member state regulators) nor those concerned that corresponding adjustment requirements would collapse supply from countries unwilling or unable to implement them, particularly in sub-Saharan Africa and Southeast Asia where adjustment infrastructure is nascent.

Limited SME Accessibility

Both ICVCM and VCMI frameworks are designed for large corporate participants with dedicated sustainability teams and legal resources. The Claims Code's requirement for a validated science-based target as a prerequisite effectively excludes most small and medium enterprises, which lack the capacity to set and validate SBTi targets. Similarly, the due diligence burden of verifying CCP compliance across a credit portfolio is prohibitive for companies purchasing fewer than 10,000 credits annually. This accessibility gap risks creating a two-tier market where large corporations enjoy reputational protection while SMEs remain exposed to greenwashing accusations.

Myths vs. Reality

Myth 1: CCP-labelled credits guarantee the emission reduction actually happened

Reality: The CCP label certifies that the crediting methodology and programme governance meet ICVCM standards. It does not provide project-level assurance that every individual credit represents a verified, additional tonne of CO2 avoided or removed. Project-level verification remains the responsibility of the crediting programme (Verra, Gold Standard, etc.) and its accredited auditors. Buyers should treat CCP status as a necessary but not sufficient quality indicator.

Myth 2: The VCMI Claims Code replaces the need for science-based targets

Reality: The Claims Code explicitly requires a validated science-based target as a prerequisite for any tier. Credits supplement, never substitute for, direct decarbonisation. Companies without SBTi-validated targets cannot make VCMI-endorsed claims regardless of credit volume or quality.

Myth 3: Voluntary market credits and compliance market allowances are interchangeable

Reality: VCM credits and compliance instruments (EU ETS allowances, UK ETS allowances, California Cap-and-Trade permits) serve fundamentally different functions. Compliance allowances are government-issued permits to emit, with supply set by regulatory caps. VCM credits represent claimed emission reductions from specific projects, with quality varying by methodology and verification rigour. Most compliance schemes do not accept VCM credits for compliance obligations, and where linkage exists (as in CORSIA for international aviation), additional eligibility criteria apply.

Myth 4: Higher credit prices always indicate higher quality

Reality: Price correlates with quality on average, but substantial exceptions exist. Nature-based removal credits from established registries can trade at $15-30 per tonne while engineered removal credits exceed $400 per tonne, yet both may satisfy CCP criteria. Price also reflects supply-demand dynamics, vintage, geography, and co-benefit attributes (biodiversity, community development) that are related to but distinct from climate integrity. Buyers should evaluate credits against CCP criteria rather than relying on price as a proxy for quality.

Key Players

Standards and Governance Bodies

ICVCM sets supply-side quality standards through the Core Carbon Principles, assessing crediting methodologies and programme governance. Its secretariat operates from London with a board comprising experts from finance, science, Indigenous Peoples organisations, and developing countries.

VCMI governs demand-side claims through the Claims Code of Practice, establishing how companies communicate their credit use. VCMI operates with support from the UK Government, the Children's Investment Fund Foundation, and several philanthropic donors.

Gold Standard applies some of the most rigorous additionality and sustainable development requirements among crediting programmes, with particular strength in clean energy and clean cookstove methodologies.

Market Infrastructure

Verra operates the Verified Carbon Standard (VCS), the largest crediting programme by volume, issuing approximately 55% of all VCM credits globally. Verra's ongoing methodology revisions, particularly for REDD+ (Jurisdictional and Nested REDD+ Framework), will significantly influence market-wide quality.

Xpansiv/CBL operates the primary spot and futures exchange for carbon credits, with daily trading volumes providing real-time price discovery for CCP and non-CCP credits.

Sylvera and BeZero Carbon provide independent credit ratings, applying quantitative and qualitative assessments to individual projects. Their ratings increasingly influence procurement decisions, particularly among institutional buyers requiring third-party due diligence.

Key Investors and Funders

Bezos Earth Fund committed $100 million to support VCM integrity infrastructure, including ICVCM operations and capacity building in developing countries.

UK Government (BEIS/DESNZ) has provided financial and technical support to both ICVCM and VCMI since their establishment, reflecting the UK's post-COP26 leadership ambitions in carbon market governance.

Action Checklist

• Audit current carbon credit portfolio against published CCP-eligible methodologies and flag non-compliant holdings
• Assess eligibility for VCMI Claims Code tiers based on current SBTi validation status and Scope 3 coverage
• Establish internal procurement policy requiring CCP-labelled credits for all new purchases from 2026
• Engage legal counsel to review existing carbon-related marketing claims against FCA anti-greenwashing rules
• Develop corresponding adjustment tracking capability for credits sourced from Article 6 participating countries
• Subscribe to independent credit rating services (Sylvera, BeZero) for portfolio-level due diligence
• Build internal capacity to evaluate crediting methodologies rather than relying solely on registry labels
• Monitor ICVCM methodology assessment pipeline for categories relevant to current procurement strategy

FAQ

Q: What is the difference between ICVCM and VCMI? A: ICVCM governs the supply side, setting quality standards for carbon credits through its Core Carbon Principles. VCMI governs the demand side, establishing rules for how companies can make public claims about their credit use. They are complementary frameworks: a company would purchase CCP-labelled credits (ICVCM supply quality) and communicate its credit use according to the Claims Code (VCMI demand-side claims). Both are needed for end-to-end integrity.

Q: Do I need CCP-labelled credits to comply with UK regulations? A: No UK regulation currently mandates CCP labels specifically. However, the FCA's anti-greenwashing rules require that environmental claims be substantiated, and CCP-labelled credits provide stronger substantiation than unlabelled alternatives. The UK Transition Plan Taskforce guidance references high-integrity credits without prescribing specific labels, but CCP alignment is widely interpreted as meeting this threshold.

Q: How much do CCP-labelled credits cost compared to standard credits? A: CCP-labelled avoidance credits traded at $12-25 per tonne in early 2026, representing a 35-55% premium over comparable unlabelled credits. Removal credits with CCP labels ranged from $80-400+ per tonne depending on technology and permanence duration. The premium reflects both genuine quality differentiation and constrained supply during the initial assessment rollout.

Q: Can startups and SMEs use the VCMI Claims Code? A: Currently, the Claims Code's requirement for a validated science-based target effectively limits participation to organisations with sufficient resources to complete the SBTi validation process. VCMI has acknowledged this gap and announced a working group in late 2025 to develop simplified guidance for SMEs, but no formal SME pathway existed as of early 2026. SMEs can still purchase CCP-labelled credits but should avoid making Claims Code tier assertions without meeting all prerequisites.

Q: Will ICVCM eventually require corresponding adjustments for all CCP credits? A: This remains one of the most contested governance questions. The ICVCM's current position is to require disclosure of corresponding adjustment status rather than mandating adjustments for CCP eligibility. However, EU regulatory developments (including the Carbon Removal Certification Framework) and growing academic consensus may pressure ICVCM to mandate adjustments by 2027-2028. Buyers should monitor this issue and consider corresponding-adjusted credits as a future-proofing strategy.

Sources

• Integrity Council for the Voluntary Carbon Market. (2025). Core Carbon Principles Assessment Framework: Methodology Assessment Results, Year One. London: ICVCM Secretariat.
• Voluntary Carbon Markets Integrity Initiative. (2025). Claims Code of Practice: Implementation Report and Early Adopter Outcomes. London: VCMI.
• Ecosystem Marketplace. (2025). State of the Voluntary Carbon Markets 2025: Market Size, Trends, and Integrity Indicators. Washington, DC: Forest Trends.
• Financial Conduct Authority. (2024). Anti-Greenwashing Rule: Final Guidance and Expectations for Environmental Claims. London: FCA.
• Trove Research. (2025). Carbon Credit Demand and Supply Projections 2025-2030: Impact of Integrity Frameworks on Market Volume. Oxford: Trove Research.
• Allen, M. et al. (2025). "Corresponding adjustments and voluntary carbon markets: implications for Article 6 implementation." Nature Climate Change, 15(2), pp. 134-142.
• UK Transition Plan Taskforce. (2024). Disclosure Framework: Guidance on Carbon Credits in Transition Plans. London: HM Treasury.