Buying carbon credits online usually takes a few minutes. The buying part is easy. What takes care is choosing the seller and checking afterwards that the credits were really retired. This guide is part of our buying guides; the guide to buying carbon credits explains the basics.
Before you buy: cut first, then count the tonnes
Reduce your own emissions first. The Oxford Offsetting Principles put cutting emissions first and treat credits as a way to deal with what remainsSource 9. Then work out the tonnes you want to cover: each credit represents a reduction or removal of one tonne of CO₂ equivalentSource 1.
For a single trip, our flight emissions calculator gives the tonnes per passenger. If you already know your total, the credits-needed calculator turns it into a number of credits and a budget.
How to buy carbon credits online, step by step
Step 1: Work out how many tonnes
Estimate the emissions you want to cover in tonnes of CO₂ equivalent, after cutting what you can. One credit covers one tonne.
Step 2: Choose a type of seller
Decide between an offset shop or retailer, a marketplace where you pick the project, or a broker for larger volumes.
Step 3: Check the listing before you pay
Look for the project name, standard, registry, project ID, vintage and price per tonne on the listing.
Step 4: Pay and keep the paperwork
Keep the receipt or certificate, the serial numbers and the link to the registry record.
Step 5: Check the retirement
Look up the serial numbers in the public registry and check the quantity and the name on the retirement.
Which kind of online seller?
Online sellers fall into a few types. Offset shops and retailers sell credits they have already chosen, usually at a fixed price per tonne. Marketplaces list many projects so you can choose one yourself. Brokers and exchanges mostly serve organisations buying larger volumes. The table is built from our provider records.
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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 |
| 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
Our where to buy carbon credits page compares individual providers on the same criteria. Standards bodies also point buyers to their own channels: Gold Standard, for example, runs a marketplace where funds go directly to project developersSource 3.
What to check on the listing
A good listing answers these questions before you pay:
- Which project? A name, a location and a project ID you can search in the registry.
- Which standard and registry? For example Verra or Gold Standard. The ICVCM’s Core Carbon Principles set a quality threshold, and credits that meet it can carry the CCP labelSource 4.
- Removal or avoidance? Removal credits take carbon out of the air; avoidance credits prevent emissions. See removal vs avoidance credits.
- When are the tonnes delivered? In the US, the FTC treats it as deceptive to suggest an offset’s reductions have already happened when they haven’t. Sellers should clearly disclose when reductions won’t occur for two years or longerSource 6.
- Price per tonne. In Ecosystem Marketplace’s survey of 2024 deals, reduction credits averaged $4.05 per tonne and removal credits $19.50Source 5. Those are averages across reported deals, not retail prices, so treat them as a guide.
If you want the lowest price, read the cheapest carbon credits first: the cheapest credits often carry the most quality risk.
After you pay: check the retirement
Retirement is what turns a purchase into an offset. Once a credit is retired, it can’t be recirculated or resoldSource 3. On the Verra Registry, ownership can only be transferred between registry accounts, and credits can’t be traded as paper certificatesSource 1, so a certificate alone proves little. Ask for the serial numbers and look them up: all issuance and retirement records are public on the Verra RegistrySource 1.
The retirement record can also show who the credits were retired for. On the Verra Registry it can name the beneficial owner if the account holder chooses to show itSource 2. Some sellers retire into a pooled record instead, so check what the seller’s terms say. Our guide to how to verify carbon credits walks through each registry.
Do you need your own registry account?
No. Most online sellers retire credits on your behalf, so you never hold them yourself. Opening your own account is a bigger step: on the Verra Registry, any entity that wants to issue, retire or transfer credits needs an active account, and every applicant goes through “Know-Your-Customer” background checksSource 7. That makes sense for organisations that trade or hold credits, not for a one-off purchase.
What you do need is evidence. Save the confirmation email, the serial numbers and the registry link in one place. If you later describe your purchase to customers or colleagues, you can point to the record instead of a certificate alone.
Red flags when buying online
Walk away if you see these
- Credits sold as an investment. The FCA says carbon credits aren’t regulated by it, and that people who bought them as an investment have reported they can’t sell or trade themSource 8.
- No project, standard or registry named. If you can’t look the credits up, you can’t check what you paid for.
- Future tonnes sold as if they exist today, with no delivery date disclosedSource 6.
- Pressure to buy now, or a cold call out of the blueSource 8.
The buyer’s checklist puts every check on one page. For more warning signs, see carbon credit scams. Buying for yourself? The guide for individuals covers flights and everyday emissions. Buying hundreds of tonnes or more? See buying carbon credits in bulk.