On-chain carbon retirement mechanics

How IMPT's on-chain carbon retirement works at the EVM level — token standards, event emissions, retirement semantics.

Direct answer

Each IMPT booking triggers a CarbonCreditNFT.retire() call on Ethereum mainnet, burning an ERC-1155 carbon-credit token and an associated IMPT ERC-20 amount, emitting a Retired event tied to the bookingRef.

Token standards

Carbon credits = ERC-1155. Each tokenId maps to a registry-side credit batch (project, vintage, registry).
IMPT token = ERC-20. Standard fungible token used as the in-platform settlement asset.
Both contracts are upgradeable proxies (v2 in production).

Retirement semantics

Retirement is irreversible by design. The ERC-1155 amount is burned (totalSupply decreases), the IMPT amount is burned, and a Retired event is emitted with the bookingRef. The retirement is then mirrored at the registry side via Thallo, so the same credit cannot be sold or counted twice on either side of the chain.

Soulbound counters

Each beneficiary address (and platform-custodied address for Web2 bookings) accumulates a soulbound retirement counter — non-transferable, non-burnable, used as proof-of-retirement for downstream attestations.

Find your hotel

Live availability across 1.7M hotels — same price as direct, free cancellation on most stays.

Search now →