# What does an A or BBB carbon credit rating actually mean?

Canonical: https://senseible.earth/answers/carbon-credit-rating-scale-meaning

On BeZero's scale, A means a high likelihood the credit achieves one tonne of CO2e avoided or removed, and BBB means a moderate likelihood. The scale runs AAA, AA, A, BBB, BB, B, C, D. Calyx uses the same eight letters for its GHG rating. A rating is an opinion on risk, not a guarantee.

## BeZero's eight notches

- AAA: highest likelihood of achieving one tonne.
- AA: very high. A: high.
- BBB: moderate. BB: moderately low.
- B: low. C: very low. D: lowest.

## What the letter does not cover

- Co-benefits such as biodiversity, jobs or SDG claims, unless they affect whether the tonne is real.
- Business risks such as fraud, default or political interference, except where they bear on carbon efficacy.
- Whether the credit suits your claim. Check removal versus reduction separately.

## Calyx letters are close, not equal

Calyx moved its GHG rating to the same eight-point scale in January 2025. Its old A+ became AAA or AA, and its old B became BBB or BB, depending on how the project scored on additionality, over-crediting, permanence and overlapping claims.

## How to use a rating

Treat it as one input alongside the registry record, the methodology version and any ICVCM CCP label. Ratings can change: BeZero monitors its ratings continuously and Calyx rates by vintage.

## What Senseible does here

Senseible's buyer view shows the record a rating rests on: the field, kiln and lab test behind a carbon removal tonne, its permanence and who signed off.

- [BeZero and Calyx compared](https://senseible.earth/answers/which-carbon-credit-rating-agency)
- [Do you need a rating?](https://senseible.earth/answers/do-i-need-a-carbon-credit-rating)
- [ICVCM Core Carbon Principles](https://senseible.earth/answers/what-are-icvcm-core-carbon-principles)
- [Carbon removal for buyers](https://senseible.earth/carbon-removal/buyers)

Sources: [BeZero Carbon, The BeZero Carbon Rating definition and rating scale (21 December 2023)](https://bezerocarbon.com/insights/the-bezero-carbon-rating-definition-and-rating-scale), [BeZero Carbon, Ratings approach: committee approval and continuous monitoring](https://bezerocarbon.com/ratings/approach), [Calyx Global, A new GHG rating scale (21 January 2025)](https://calyxglobal.com/research-hub/ratings-approach/a-new-ghg-rating-scale/)

Last reviewed 2026-11-02.