Credit vintage
The period in which a credited reduction or removal occurred, as defined by a programme.
Example
Two credits sold on the same date can have different vintages.
The catch
Purchase date and environmental outcome date are separate facts.
In more depth
Credit vintage, explained.
Credit vintage tells a buyer how fresh the climate benefit is, and older vintages often come from projects approved under rules that have since tightened. Many buyers prefer recent vintages for that reason, and some compliance schemes accept only credits from a defined recent period. Issuance can also trail the vintage by years, because verification happens after the monitoring period ends.
Timing affects any claim. Using a credit from long ago to balance this year's emissions leaves today's tonnes in the atmosphere with no contemporary reduction beside them. State the vintage alongside the project name and retirement date whenever you report a carbon credit.