A carbon credit registry is a system that records and tracks the issuance, transfer, and retirement of carbon credits. Registries are essential for ensuring the transparency, integrity, and efficiency of the carbon credit market.

Issuance of Credits
After a carbon reduction project has been verified and validated according to specific standards, registries issue carbon credits. Each credit typically represents one metric ton of CO2 equivalent emissions reduced or removed from the atmosphere.

Unique Serial Numbers
Each carbon credit gets a unique serial number, which helps in tracking its entire lifecycle - from issuance to final retirement, to ensure credits are not double-counted or fraudulently claimed.

Tracking Ownership
Registries maintain a record of the current and past owners of each carbon credit. This is important for ensuring the transparency of transactions and for audit purposes.

Retirement of Credits
When a credit is used to offset emissions, it is "retired" in the registry to prevent its reuse. This retirement is recorded and often publicly available, providing proof that the offset has occurred.

Market Transparency
By maintaining comprehensive records, registries contribute to the transparency of the carbon market, allowing buyers and sellers to have confidence in the validity and origin of the credits they are dealing with.

Compliance with Standards
Registries ensure that all credits comply with specific standards and methodologies.

Public Access and Reporting
Many registries provide public access to certain data, allowing external parties to verify transactions and the retirement of credits.

Facilitating Trade
Registries facilitate the buying and selling of credits by providing a reliable platform for transactions. They often interface with other trading platforms and financial markets.

Supporting Multiple Project Types
Registries can handle credits from a variety of project types, such as methane reduction, renewable energy, reforestation, or energy efficiency projects.

Global and Regional Regisries
Global and regional carbon credit registries exist, each serving different markets and complying with various regulatory requirements.