How to Buy Carbon Credits: A Checklist Before You Close the Deal

If you want to buy carbon credits, the first decision is not which project to pick but which route to buy through. A company offsetting a single event, a mid-sized firm covering its annual footprint and a multinational signing multi-year removal contracts use different channels, with different minimum volumes, prices and paperwork. This guide compares those routes, shows the step-by-step purchase flow and lists what to check before paying. If you are new to the topic, start with what carbon credits are and how they work.

Disclosure: ESG Minute is part of the B21 group, which also operates Credita Carbon, a carbon credit retailer. This guide does not rank or recommend sellers.

The main ways to buy carbon credits

The Carbon Offset Guide describes six acquisition methods, which can be grouped into five practical routes for most buyers.

1. Online marketplaces and retailers

Retailers and online marketplaces sell credits from a catalogue of projects, usually with card payment and an instant certificate. The Carbon Offset Guide notes that retailers are the most convenient option for individuals and small companies, but are “likely to be the highest priced option” and may offer limited transparency on quality. This route fits small and occasional purchases, from a fraction of a tonne up to a few thousand tonnes.

2. Brokers

Brokers are intermediaries that source credits from multiple projects and negotiate on the buyer’s behalf. According to the Carbon Offset Guide, they give quick access to diverse project types and better information than an exchange, at a higher cost than buying directly, and with a possible bias if the broker owns the projects it sells. This route fits companies buying recurring volumes that want help with sourcing but do not have an in-house carbon team.

3. Directly from project developers

Buyers can purchase unsold credits from a developer (a spot purchase) or sign a forward contract, often called an Emission Reduction Purchase Agreement (ERPA), for credits the project will deliver in the future. The Carbon Offset Guide lists lower cost and a direct understanding of the project as advantages; the drawbacks are that available inventory is hard to find and forward contracts involve waiting two to three years and a long-term commitment. This route fits larger buyers with the capacity to run their own due diligence.

4. Registry-linked marketplaces

Some standards run or host their own storefronts. The Gold Standard Marketplace sells credits from several developers by the tonne and retires them in the Gold Standard Impact Registry on the buyer’s behalf. This route fits buyers who want a direct link between the purchase and the registry record.

5. Environmental exchanges

Exchanges list standardised carbon contracts for members and trade in large volumes. The Carbon Offset Guide describes them as quick and competitively priced, but with limited quality information and not viable for small purchases. Access is usually through membership or a broker that is a member. This route fits traders, large corporate buyers and intermediaries.

Comparison of routes to buy carbon credits

Examples of marketplaces and sellers

The examples below are listed alphabetically, only to illustrate how each route works in practice. Information comes from each organisation’s own website, accessed in September 2026. Inclusion is not an endorsement.

• ACX (formerly AirCarbon Exchange): a digital exchange for carbon credits and renewable energy certificates that reports more than 190 active trading members in over 30 countries and lists regional operations in Singapore and Brazil.
• Carbonmark: an online marketplace where buyers select a project and tonnage, pay by card or bank transfer and receive a public retirement certificate. It states that it supports purchases from 0.001 to 1,000,000 tonnes and offers an API for programmatic retirements.
• ClimeCo: sells carbon credits through an online shop, as one-time or recurring purchases starting from a single credit, with a certificate issued after purchase.
• Gold Standard Marketplace: sells credits from multiple developers and retires them in the Gold Standard Impact Registry. According to the marketplace, retired credits are non-refundable, and organisations buying USD 10,000 or more within 12 months must complete an “Approved Buyer” registration before an invoice is issued.
• Puro.earth: a carbon removal standard that issues CO2 Removal Certificates (CORCs). It states that it discontinued its online marketplace in 2022 and does not act as a counterparty: buyers negotiate spot purchases or offtakes with accredited suppliers or through third-party platforms, then retire CORCs from their own Puro Registry account.
• Terrapass: a retailer offering one-time and subscription offsets for individuals and businesses, with credits certified by Gold Standard, Verified Carbon Standard, Climate Action Reserve or American Carbon Registry.
• Xpansiv CBL: a spot marketplace for environmental commodities that describes itself as the world’s largest, with more than 1,100 participants, same-day settlement through a network of over 15 registries, and standardised contracts such as GEO CCP and CORSIA-eligible contracts.

How to buy carbon credits step by step

1. Define the goal and the claim. Decide what the credits are for: compensating residual emissions, a product or event claim, or a compliance obligation. The claim determines the type, volume and quality you need. See carbon neutral vs net zero for how claims differ.
2. Choose avoidance or removal. Avoidance credits (for example renewable energy or avoided deforestation) prevent emissions; removal credits (for example reforestation or biochar) take carbon out of the atmosphere. Engineered removals such as biochar trade far above the market average, as the price data below shows.
3. Choose the standard. Common standards include Verra (VCS), Gold Standard, Climate Action Reserve, American Carbon Registry and, for engineered removals, Puro.earth. Check whether the methodology carries the ICVCM Core Carbon Principles (CCP) label if that matters for your claim.
4. Get quotes. Ask at least two or three sellers from different routes for the same specification: project, vintage, standard, volume and delivery date. Ask whether the price includes retirement and fees.
5. Check the credits in the registry. Before paying, search the project and serial numbers in the public registry (for example the Verra Registry) and confirm the credits exist, are issued and are not already retired.
6. Sign the contract. For larger purchases, the contract should state the serial numbers or delivery terms, who retires the credits and when, and what happens if credits are invalidated or not delivered.
7. Retire the credits in your name. Retirement permanently removes credits from circulation; the Carbon Offset Guide notes that retired credits cannot be transferred again. The beneficiary field should name your organisation and, ideally, the purpose and reporting year.
8. Keep the certificate and the registry link. Store the retirement certificate, serial numbers and registry link with your emissions inventory so auditors and stakeholders can verify the claim.

What to check before paying

A short pre-payment list covers most risks:

• The credits appear in a public registry, with issued status and serial numbers that match the offer.
• The project is additional: the reduction or removal would not happen without credit revenue.
• The methodology, vintage and project type fit the claim you intend to make.
• The seller can say who retires the credits, in whose name, and when you will receive proof.
• For credits linked to international transfers, whether a corresponding adjustment under Paris Agreement Article 6 is needed or offered.

For the full process, including permanence, leakage and reputational checks, see our deep-dive on due diligence before buying carbon credits.

How much carbon credits cost

The most widely cited dataset on voluntary market prices is Ecosystem Marketplace’s State of the Voluntary Carbon Market 2025, which covers transactions reported for 2024:

• The average price across all credits fell from USD 6.71 per tonne of CO2e in 2023 to USD 6.34 in 2024.
• Reported transaction volume was 84.4 million tonnes, with a total value of USD 535.1 million.
• Forestry and land use credits averaged above USD 9 per tonne.
• Biochar production credits, an engineered removal type, averaged over USD 165 per tonne, but made up less than one percent of reported transactions.

Ecosystem Marketplace notes that these figures are lower-bound estimates based on data from its survey respondents, and that individual prices vary with volume discounts and project quality. Retail prices are usually higher than these averages. For a broader view of what buyers pay in 2026, see carbon credit prices in 2026.

Buying carbon credits in Brazil

Brazilian buyers can use any of the routes above, but a few local points matter:

• Invoicing in BRL. Buying from a seller established in Brazil allows payment and invoicing in reais, which can simplify accounting compared with an international purchase. Ask for an invoice that identifies the project, serial numbers and retirement.
• Law 15,042/2024 and the SBCE. Law 15,042 of 11 December 2024 created the Brazilian Emissions Trading System (SBCE). It defines the CRVE (Verified Emission Reduction or Removal Certificate) as a tradable asset representing one tonne of CO2e, following an accredited methodology and registered in the SBCE. Voluntary carbon credits only become CRVEs if they use a methodology accredited by the SBCE managing body, are independently verified and are recorded in the SBCE Central Registry (Art. 44).
• Who is regulated. Installations emitting more than 10,000 tCO2e per year must monitor and report; those above 25,000 tCO2e must also reconcile their obligations (Art. 30). Regulated operators may use CRVEs up to a maximum percentage set in the National Allocation Plan (Art. 12). The law sets a phased implementation, starting with a regulation period (Art. 50). See our SBCE explainer.
• Tax and securities rules. Revenues from selling carbon credits are not subject to PIS/Cofins (Art. 19), and carbon credits traded in the financial and capital markets are treated as securities under the CVM law, while private placements outside those markets are not (Art. 14).
• Exchange infrastructure. B3, the Brazilian stock exchange, states that it launched a carbon credit registration environment in 2023 and announced a partnership with ACX to give its clients access to a global trading platform.

Frequently asked questions about buying carbon credits

Related: what a carbon offset is.

Sources

• Carbon Offset Guide: How to acquire carbon credits
• Ecosystem Marketplace: State of the Voluntary Carbon Market 2025
• Brazil, Law 15,042 of 11 December 2024
• B3: ASG, Balcão
• Verra: Verra Registry
• Gold Standard Marketplace
• Puro.earth: Buy carbon credits
• Carbonmark: Buy carbon credits
• ClimeCo: Purchase credits
• Terrapass
• Xpansiv CBL
• ACX