Circle gives legacy USDC apps 95 days before old cross-chain transfer routes stop working

Circle announced that the first version of its Cross‑Chain Transfer Protocol (CCTP V1) will be deprecated, giving developers 95 days to migrate to the newer version before legacy contracts stop processing USDC transfers.

Key dates and limits

• Oct. 31 – Burn limits for CCTP V1 begin to decrease. A burn limit caps the amount of USDC that can be destroyed on one chain for reminting on another.

• November – Capacity on V1 contracts is progressively reduced.

• Dec. 1 – All CCTP V1 contracts are paused. Any integration still pointing to V1 will no longer be able to move USDC across chains.

Migration requirements

Developers must update their code to use CCTP V2, which uses new contract addresses, interfaces and APIs. Required changes include:

• Pointing to the V2 TokenMessenger, MessageTransmitter and TokenMinter contracts.
• Updating contract interfaces and replacing calls to depositForBurn with the V2 version that adds parameters for permitted destination caller, maximum fee and minimum finality threshold.
• Switching attestation calls to the /v2/messages/{sourceDomainId} endpoint.
• Selecting standard or fast settlement where available and handling associated fees.

Impact on supported chains

Circle’s current matrix lists 27 blockchains on the CCTP network. Among them, Aptos, Noble and Sui are supported only by CCTP V1. Transfers involving these chains will continue to rely on the legacy network unless integrators adopt alternative routes.

Assurance for users

Circle’s migration guide states that users will retain access to their funds throughout the phase‑out, and pending redemptions will remain available. The company will keep sufficient minting capacity to complete outstanding attestations before the V1 contracts are fully paused.