Buying a few tonnes is a shopping task. Buying thousands is a procurement project, with contracts, due diligence and reporting attached. This guide covers how organisations buy carbon credits in large volumes. It is part of our buying guides; for the wider corporate picture, see how to buy carbon credits for a company.
Start with the volume and what the credits are for
Bulk purchases should come after your own reductions. The SBTi’s Corporate Net-Zero Standard says credits must not be counted as reductions towards science-based targets. They may only be used to neutralise residual emissions or to finance mitigation beyond a company’s targetsSource 1. VCMI’s Claims Code expects companies to set short-term reduction targets first, then buy high-quality credits from outside their value chainSource 2.
That choice shapes the order. Neutralising residual emissions points towards durable removals, and the Oxford Offsetting Principles ask buyers to shift towards removals with a low risk of reversal over timeSource 14. Once you know the tonnes, our credits-needed calculator turns them into a number of credits and a budget range.
How to buy carbon credits in bulk
Step 1: Fix the volume and the role of the credits
Work out the tonnes after your own reductions and decide whether the credits neutralise residual emissions or fund mitigation beyond your value chain.
Step 2: Write your criteria
Set project types, standards, vintages, CCP label, rating thresholds, removal share and budget per tonne.
Step 3: Choose a route to market
Use a request for proposals, a broker, an exchange or a forward offtake, depending on volume and timing.
Step 4: Compare offers on the same terms
Ask every supplier for the project and registry ID, methodology, vintage, volume, price per tonne and delivery date.
Step 5: Do due diligence and contract
Check the methodology, label, ratings and registry records, then agree delivery, retirement and evidence in the contract.
Step 6: Retire and disclose
Make sure credits are retired in your organisation’s name and report them separately from your emissions inventory.
Routes to market for large volumes
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| Route | How it works | Suits |
|---|---|---|
| Request for proposals | You send your criteria to several suppliers and compare their offers | Buyers with clear criteria who want competing bids |
| Broker | A broker sources credits that match your criteria and negotiates for you | Buyers without an in-house carbon team |
| Exchange or trading platform | You buy standardised contracts or listed credits, usually through a registry account | Buyers who trade regularly and can hold credits |
| Forward offtake | You agree to buy credits a project will deliver in future years | Buyers who want a long-term supply, often of removals |
Exchanges and trading platforms work differently from shops. Xpansiv’s CBL, for example, describes itself as a spot marketplace for environmental commodities. It offers standardised contracts and lets sellers use its order book, auctions or requests for quotesSource 11. On the Verra Registry, credits can only move between registry accountsSource 8, and every account applicant goes through “Know-Your-Customer” checksSource 9. If you don’t want to hold credits yourself, ask a broker or retailer to retire them for you.
The table below shows the provider types in our records that say they serve companies.
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| Type | How you buy | Serves (from our records) | Examples |
|---|---|---|---|
| Retailer / offset shop | Sells credits it has already chosen, often at a fixed price per tonne, and retires them for you | Individuals, Small businesses, Companies | BuyCarbonOffsets.org *, Cool Effect, Ecologi |
| Marketplace | Lists credits from many projects or sellers, so you choose the project | Individuals, Small businesses, Companies | Carbonmark, Gold Standard Marketplace, Supercritical |
| Broker | Sources and negotiates credits for an organisation, usually through a sales conversation | Small businesses, Companies | Climate Impact Partners, Patch |
| Exchange | Trading platform with standard contracts for organisations and traders | Companies | Climate Impact X (CIX) |
| Project developer | Runs or finances its own projects and takes money for them directly | Individuals, Small businesses, Companies | atmosfair, myclimate |
* Same operator · DisclosureWho each type serves and the examples come from the providers' own pages. Examples are listed alphabetically, not ranked.As of Oct 2026
Due diligence at volume
Large purchases deserve project-level checks, not only a look at the label.
- Methodology and CCP label. The ICVCM’s Core Carbon Principles set a quality threshold, and credits that meet it can carry the CCP labelSource 3. The label works at the level of whole methodologies: in August 2024 the ICVCM decided that credits from eight current renewable energy methodologies would not receive itSource 4.
- Independent ratings. BeZero Carbon assesses six risk factors, including additionality, over-crediting and non-permanenceSource 5. Sylvera rates projects on a scale from AAA to DSource 6. Calyx Global evaluates additionality, over-crediting, permanence and overlapping claimsSource 7.
- Registry records. Check issuance and retirement records yourself. All VCU issuance and retirement records are public on the Verra RegistrySource 8.
- The developer. In 2024 the US CFTC brought its first fraud actions in the voluntary carbon market, against a project developer that reported false information to obtain more credits than it was entitled toSource 15. Ask who verified the project and when.
Our guide to how to verify carbon credits walks through each registry.
Contract terms to agree
Put these in writing
- Delivery date. Spot credits exist today; forward credits don’t yet. US guidance treats it as deceptive to suggest an offset’s reductions have already happened when they haven’t, and sellers should clearly disclose when reductions won’t occur for two years or longerSource 13.
- Retirement and evidence. Who retires the credits, when, and in whose name. On the Verra Registry, the retirement record can name your organisation as beneficial owner if the account holder chooses to show itSource 10.
- Serials and project details for every tranche, so each delivery can be checked.
- What happens if a credit can’t be delivered or a project loses its registration.
Budgeting for a bulk purchase
Price depends far more on the mix than on the volume. In Ecosystem Marketplace’s survey of 2024 deals, removal credits averaged $19.50 per tonne and reduction credits $4.05Source 12. These are averages of reported transactions, so use them to frame a budget rather than as a quote. Our page on removal vs avoidance credits explains the difference, and the cheapest carbon credits covers the trade-offs of buying on price.
Reporting what you bought
Claims: report credits separately
The SBTi standard says companies should disclose carbon credits separately from their greenhouse gas inventory, and make clear that progress against targets doesn’t include themSource 1. Describe what you funded, with tonnes, projects and registry links, rather than a neutrality claim.
If your organisation is planning a large purchase, the form below sends an enquiry to BuyCarbonOffsets.org, the offset shop run by the same team as this site. To compare other sellers, see where to buy carbon credits; for smaller amounts, how to buy carbon credits online is quicker.