“Carbon credit” and “carbon offset” are used as if they meant the same thing, and in everyday speech they often do. The difference matters when you describe what your purchase achieved. This page sets out how the leading guidance defines each term and what that means for the claim you make.
It builds on what a carbon credit is, part of our Learn section.
What is a carbon credit?
A carbon credit is a unit of carbon dioxide reduced or removed, generated by a projectSource 1. The Oxford Offsetting Principles describe credits as tradeable certificates that represent the reduction or removal of a set amount of greenhouse gas emissionsSource 1. In the voluntary market each credit stands for one tonne of CO₂ equivalent: Verra defines its units this waySource 3, and so does Gold StandardSource 4.
A credit is a record in a registry. It can be bought, sold and finally retired, after which it can’t be recirculated or resoldSource 4.
What is a carbon offset?
An offset is a use of that reduction or removal. The Oxford Principles define an offset as an emissions reduction or removal, from an action outside an organisation’s boundaries, that is used to counterbalance the organisation’s residual emissionsSource 1.
So the credit is the certificate, and offsetting is one thing you can do with it: retire it and count the tonne against your own emissions.
How do the two terms compare?
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| Aspect | Carbon credit | Carbon offset |
|---|---|---|
| What it is | A tradeable certificate for one tonne of CO₂e reduced or removed | The use of a reduction or removal to balance your own emissions |
| Where it lives | In a registry account, with a serial number | In your emissions accounting and your public claim |
| Needs the other? | No: a credit can be retired without an offset claim | Yes: an offset claim rests on retired credits |
As of Oct 2026
The Oxford Principles make the same point: credits are often used to offset emissions, but they can also be bought and retired without being used as an offset, as extra mitigation beyond your own value chainSource 1.
Why the difference matters for your claim
Leading guidance is moving away from treating credits as a way to cancel out emissions you could still cut.
- VCMI (the Voluntary Carbon Markets Integrity Initiative) says credits must be used in addition to, and not to delay or displace, deep decarbonisation, and that they cannot be counted towards a company’s own value-chain reduction targetsSource 2. It frames credit use as “beyond-value-chain mitigation”Source 2.
- The Oxford Principles ask organisations to cut emissions first, and to use credits for residual emissions with a growing share of carbon removals over timeSource 1.
In practice there are two kinds of claim:
- An offset claim. You count the retired tonnes against your own remaining emissions.
- A contribution claim. You say you funded a stated number of tonnes of reductions or removals, without claiming they cancel out your emissions.
Careful with neutrality claims
The Oxford Principles note that “carbon neutral” has come to be read as a less rigorous, interim claim, in which an organisation buys credits to cover its remaining emissions, often well before reaching net zeroSource 1. A factual contribution claim, such as the number of tonnes you retired with a link to the registry record, is clearer and easier to back up.
What this means when you buy
Whichever word your seller uses, check the same things: the credits are retired, not just sold to you; the registry record names you or your organisation; and the serial numbers match. Our guide to carbon credit retirement shows how to check, and removal vs avoidance credits explains the two kinds of tonne you can buy.