Ex-ante and Ex-post Credits
Ex-post credits are issued after the reduction or removal has occurred and been verified. Ex-ante credits are sold in advance, based on outcomes a project expects to deliver in future.
Why the ex-ante and ex-post distinction matters for carbon credit buyers
The distinction comes down to whether the tonne exists yet. Ex-post credits carry no delivery risk and can be retired immediately, while ex-ante purchases fund projects before they perform, usually at a lower price in exchange for accepting that risk. Most registries issue only ex-post, so ex-ante volumes are typically contracted as forward agreements rather than held in a registry account. Ratings reflect the difference too: BeZero applies an Apre rating to projects assessed before delivery, which signals greater uncertainty than a rating on credits already issued.