Retirement is the step that turns a carbon credit you own into a tonne you can claim. Until a credit is retired, it is just an asset in a registry account that could be sold again. This page explains what retirement means, what the record shows and how to check it yourself.

For the full journey of a credit, start with what a carbon credit is, part of our Learn section.

What does it mean to retire a carbon credit?

Retiring a credit cancels it in the registry for good. Verra describes retired units as taken out of circulationSource 1, and Gold Standard says retired credits can’t be recirculated or resoldSource 4.

Retirement is the last of the four steps every credit goes through.

  1. 1

    CreatedVerified

    A project cuts or removes emissions; an auditor checks the numbers.

  2. 2

    IssuedActive

    A registry issues one credit per tonne, each with a serial.

  3. 3

    SoldTransferred

    A shop, marketplace or broker transfers it to you.

  4. 4

    RetiredRetired

    Cancelled in your name for good. Can’t be resold.

Fig. 1 — The life of a carbon credit. A credit counts toward a claim only at step 4.

Credits are often retired to offset emissions, but they can also be retired as a contribution to climate action without an offset claimSource 6. Our page on credit vs offset explains the difference.

Why does retirement matter?

Retirement is what stops one tonne being claimed twice. Once a credit is retired, nobody else can buy it or retire it again, so the claim attached to it belongs to one buyer. Avoiding double counting is one of the ICVCM’s ten Core Carbon Principles, alongside tracking and transparencySource 5.

You don’t need your own registry account. A seller can retire credits on your behalf, and on the Verra Registry the beneficial owner field is where your name or your organisation’s name appearsSource 2. Ask for it to be shown publicly, so anyone can check your claim.

Who keeps the record?

Each standard runs its own public registry:

  • Verra Registry (registry.verra.org) tracks the generation and retirement of every Verified Carbon UnitSource 1.
  • Gold Standard Impact Registry (registry.goldstandard.org) is where Gold Standard credits are issued, held, transferred and retired. Every issued credit gets a unique serial number, so it can be traced from generation to sale and retirementSource 3.

If a seller can’t tell you which registry holds your credits, treat it as a warning sign.

What does a retirement record show?

A public retirement record is the proof behind any claim. On the Verra Registry, retirement records show the serial numbers, the retirement reason, details of the reason and the beneficial owner. The last three are optional and stay private if the account holder choosesSource 2.

Registry record · exampleRetired

EX-0042-KE-2025-000118–000129

Project
Example cookstove project, Kenya
Quantity
12 tCO₂e
Retired for
Jane Doe
Vintage
2025

The card above is an example, not a real record. A real one lists the project, the quantity, who the credits were retired for and the vintage, with serial numbers you can search for.

When you buy through Gold Standard’s own marketplace, you get a certificate with a link to the registry record where your credits have been retiredSource 4.

How to check a retirement yourself

Our step-by-step guide to how to verify carbon credits covers more registries and what to check in each. In short:

  1. Step 1: Get the serial numbers

    Ask the seller for the serial numbers or serial range of the credits retired for you, and the registry they are in.

  2. Step 2: Open the public registry

    Go to the standard’s registry, such as the Verra Registry or the Gold Standard Impact Registry, and search its retirements.

  3. Step 3: Match the record

    Check that the serial numbers, quantity and date match what you were sold, and that the credits are marked as retired.

  4. Step 4: Check the beneficiary

    Look for your name or your organisation’s name. If it is hidden, ask the seller to retire future credits with the beneficiary shown.

No serial numbers, no proof

If a seller can’t show you serial numbers in a public registry, or won’t retire credits in your name, you can’t verify that the tonnes are yours, or that they haven’t been sold to someone else.

Where to go next

Before you buy, decide what kind of tonne you want: removal vs avoidance credits explains the choice. When you are ready, our guide to buying carbon credits takes you through it step by step.