Buying carbon credits is the easy part. Understanding the market you are buying in is harder, because nobody runs it. There is no exchange that lists every credit, no regulator that approves every project and no single rulebook for what you may claim afterwards.
The voluntary carbon market (VCM) is where companies buy carbon credits without a legal obligation, usually to take responsibility for emissions they have not yet cut. Each credit represents one tonne of CO2 equivalent (tCO2e) avoided or removed by a project and certified by an independent standard. This article explains who supplies those credits, who checks them, who decides what you can claim with them, and how prices are set.
Voluntary vs compliance: the one difference that matters
In a compliance market such as the EU Emissions Trading System, the law caps the emissions of power plants, factories and airlines and requires them to hand in allowances for every tonne. In the voluntary market, nobody has to buy anything. Companies buy credits because of their own climate targets, customer expectations or investor pressure.
The two markets are very different in size. Direct carbon pricing, mostly emissions trading systems and carbon taxes, raised more than USD 107 billion for governments in 2025 and covers just over 29% of global emissions (World Bank, May 2026). The voluntary market’s reported transaction value in 2024 was USD 535 million (Ecosystem Marketplace, State of the Voluntary Carbon Market 2025).
The line between them is getting thinner, as the section on rules shows. For a full side-by-side comparison, see voluntary and compliance carbon markets: the difference. This article stays with the voluntary side.
How big is the voluntary carbon market?
Smaller than its reputation, and harder to measure than it should be. Ecosystem Marketplace, which surveys traders and registries every year, reported USD 535 million in transaction value for 2024, down 29% on 2023, with volume at its lowest since 2018. Retirements, the moment a credit is actually used, held up better at around 182 million tCO2e across the main standards.
For 2025, data providers disagree. Some report slightly lower retirements than in 2024, others growth, depending on which registries and which credit types they count. If a supplier quotes you a single market-size figure, ask which dataset it comes from.
Two numbers matter more to a buyer than the total. First, quality now has a visible price: removal credits traded at more than 25 times the market average in 2024, and buyers paid a 217% premium for recent vintages (Ecosystem Marketplace). Second, the gap between low-rated and high-rated credits keeps widening, which is why our overview of carbon credit prices in 2026 reports prices per quality tier.
Who is in the voluntary carbon market
A credit passes through several hands between the project and your sustainability report:
Role | What they do | Examples |
|---|---|---|
Project developer | Designs and runs the project that avoids or removes emissions | forest, cookstove, biochar or direct air capture developers |
Standard and registry | Sets the methodology, issues credits with serial numbers, records retirements | Verra (VCS), Gold Standard, ACR, Climate Action Reserve, Plan Vivo, Puro.earth, Isometric |
Validation and verification body (VVB) | Audits the project before registration and each monitoring period before issuance | accredited audit firms |
Rating agency | Scores project quality independently of the standard | BeZero, Sylvera, Calyx Global |
Intermediary | Sources, bundles and resells credits | brokers, traders, exchanges, platforms, retail providers |
Buyer | Retires credits against its emissions or for a contribution claim | companies, public bodies, airlines under CORSIA |
Where you buy in this chain changes what you pay and what you can verify. A broker gives you access, a platform gives you a catalogue, a developer gives you one project, and a provider such as Regreener does the due diligence and portfolio design. Our article on brokers, marketplaces and developers compares the routes.
Who sets the rules in a market without a regulator
This is the part buyers most often get wrong. The voluntary market has at least four rulebooks, and each answers a different question.
Is the credit any good? The ICVCM
The Integrity Council for the Voluntary Carbon Market sets the Core Carbon Principles (CCP), a benchmark for additionality, permanence, robust quantification, no double counting and safeguards. It assesses both the standards and their methodologies. As of August 2026, 13 crediting programmes are CCP-Eligible and 45 methodologies are CCP-Approved (ICVCM assessment status). Credits from an approved methodology, issued by an eligible programme, can carry the CCP label.
The label is a floor. It approves a methodology, not every project that uses it, which is why rating agencies and buyer due diligence still matter. Our CCP-labelled carbon credits overview shows what is available.
What may you claim? VCMI and SBTi
The Voluntary Carbon Markets Integrity Initiative (VCMI) publishes the Claims Code of Practice, which sets conditions for companies that want to make a public claim about their credit use: a science-aligned target, progress against it, and credits that meet the CCP benchmark.
The SBTi Corporate Net-Zero Standard V2.0, published in June 2026, decides how credits relate to science-based targets. They do not count towards scope 1, 2 or 3 reduction targets. They are recognised as action beyond the value chain, and larger companies must support eligible carbon removals from 2035, starting at 1% of ongoing emissions (SBTi carbon removal requirements).
What does the law allow? EU rules
The voluntary market is increasingly shaped by law that was not written for it:
Consumer law. From 27 September 2026, the EU Empowering Consumers Directive bans claims towards consumers that a product is carbon neutral, reduced or positive because of offsetting. Contribution claims remain possible. See the EmpCo carbon neutral claim ban.
Reporting. Companies reporting under the CSRD disclose credits separately from their emissions inventory (carbon credits in CSRD reporting).
Certification. The EU’s own removals framework, the CRCF (Regulation (EU) 2024/3012), will add a government-backed label for removals and carbon farming. The first certified units are not expected before late 2027 (CRCF certified carbon credits).
Where do the tonnes count? Host countries and Article 6
Under Article 6 of the Paris Agreement, a host country can authorise credits for use abroad and apply a corresponding adjustment, so the tonne is not also counted in its own climate target. Most voluntary credits are not authorised, and for a contribution claim they do not need to be. Authorisation does matter for airlines buying under CORSIA, which accepts only authorised units in its first phase (buying CORSIA credits), and it is becoming a selling point in some long-term contracts.
Tip from Bernard de Wit, Founder of Regreener: “When a client asks whether a credit is ‘good’, we answer in four parts: is the methodology approved, how does the project itself score, what will you claim with it, and does that claim hold in the markets where you sell. A credit can pass the first two and still be the wrong purchase if the claim you have in mind is one your regulator no longer accepts.”
How prices are set in the voluntary carbon market
There is no single market price. A credit’s price depends mainly on five things:
Project type. Avoidance credits such as forest protection or renewable energy sit at the low end; durable removals such as biochar and direct air capture cost many times more.
Quality signals. A CCP label, a high independent rating and a clean track record raise the price.
Vintage. Recent vintages trade at a premium over older ones (what a carbon credit vintage tells you).
Co-benefits and certification extras, such as biodiversity or community labels.
Contract form. Spot purchases, forward contracts and multi-year offtakes are priced differently (spot vs forward vs offtake).
Most transactions happen over the counter, so prices are negotiated, not published. That is why two quotes for “the same” credit can differ widely. Our quote comparer shows which of these five factors explains the gap in yours, and why carbon credit quotes differ goes through the usual causes.
What changed for buyers in 2025 and 2026
Three shifts define the market a buyer meets today.
Quality became a price tier. Buyers who once bought the cheapest available tonne now pay for ratings, recent vintages and CCP labels, and low-rated credits are hard to use in public communication.
Removals moved into the budget. SBTi V2 turned removals from a 2050 question into an annual requirement from 2035 for larger companies. Combined with scarce supply of durable removals, that pushes buyers towards multi-year offtake agreements.
Claims tightened. EU consumer law, national regulators such as the Dutch ACM and the VCMI all push in one direction: say specifically what you financed, keep it separate from your own emissions, and do not call products neutral.
“The companies that do well in this market treat a credit purchase like any other procurement with reputational risk: a written quality policy, a named project, evidence on file. The ones that get into trouble usually bought a tonne and a claim in one package without checking either.”
Bernard de Wit, Founder of Regreener
How a company takes part
For most European companies the route looks like this:
Measure the footprint and set a reduction target. Credits come after.
Decide the purpose: a contribution claim, a step towards SBTi’s removal requirement, or both.
Write a short quality policy: accepted standards, minimum rating or CCP label, avoidance-removal mix, maximum vintage age.
Choose a buying route and request quotes for named projects.
Retire in your name and keep the registry evidence with your report.
Our quality framework is the checklist we apply to every project before it reaches a client, and how carbon credits work follows a single credit from project to retirement.
Buying in the voluntary carbon market?
Tell us what you want to achieve with credits and we will show you which projects fit, what they cost and what you can claim with them.
