TL;DR
- Circle set December 1 as the deadline to pause V1 contracts of its USDC cross-chain transfer protocol.
- Burn limits will begin decreasing on October 31, giving integrators 95 days to migrate to the new standard.
- Aptos, Noble, and Sui are the only chains that rely exclusively on the V1 network and will be left without a native route once the contracts are closed.
Circle gave developers still operating on the first version of its Cross-Chain Transfer Protocol (CCTP) a 95-day window to complete the migration before the legacy contracts stop processing USDC transfers between chains.
The timeline is precise: CCTP V1 burn limits will begin decreasing on October 31, 2026. A burn limit determines how much USDC can be destroyed on a source chain to be minted on a destination chain. Throughout November, the company will progressively reduce that capacity until the contracts are definitively paused on December 1. Any integration still pointing to V1 on that date will no longer be able to move USDC between networks.
Circle Forces Migration to the New CCTP
The transition requires substantial code changes. CCTP V2, now simply called CCTP, uses different contract addresses, interfaces, and APIs, incompatible with the previous version. Integrators must update their references to TokenMessenger, MessageTransmitter, and TokenMinter, modify calls to depositForBurn —which in V2 incorporates parameters for the allowed recipient, the maximum fee, and the minimum finality threshold— and replace legacy attestation calls with the /v2/messages/{sourceDomainId} flow.
Circle clarified that users will retain access to their funds during the transition phase and that pending redemptions will remain available. The company also guaranteed sufficient minting capacity to complete in-progress attestations before the definitive closure of V1.
Aptos, Noble, and Sui: Upgrade or Walk Away
Of the 27 chains currently integrated into the CCTP network, three rely exclusively on the legacy protocol: Aptos, Noble, and Sui. Any native route to or from these networks will continue operating on V1 until December 1, unless integrators adopt a separately documented alternative.
Circle did not publicly identify which exchanges, wallets, bridges, or applications are still using the legacy contracts, so the number of production integrations affected by the closure has not been specified. As a historical reference, the company reported in November 2025 that CCTP had processed more than $110 billion across 5.3 million transfers combining V1 and V2 activity.
