Circle has set a clear deadline for developers still using the first version of its Cross-Chain Transfer Protocol. The company is deprecating CCTP V1 and giving integrations 95 days to move before the old contracts stop handling USDC transfers. The clock starts with reduced burn limits on Oct. 31. By Dec. 1, V1 contracts will be paused.
Burn limits matter because they cap how much USDC can be destroyed on one chain so it can be reminted on another. Circle says it will lower those limits and reduce transfer capacity through November. After Dec. 1, any integration still pointing to V1 will no longer move USDC across chains.
What changes for developers
Migrating is not a simple address swap. CCTP V2, now called just CCTP, uses new contract addresses, interfaces, and APIs. It is not compatible with V1. Developers must point to the V2 versions of TokenMessenger, MessageTransmitter, and TokenMinter. They also need to update calls to depositForBurn and handle new parameters for permitted destination caller, maximum fee, and minimum finality threshold.
The attestation flow is also changing. Teams should replace legacy attestation calls with the /v2/messages/{sourceDomainId} endpoint, choose standard or fast settlement where available, and account for fees. Circle’s migration guide says users will keep access to funds during the phase-out and pending redemptions remain available. The company also said it will keep enough minting capacity to complete outstanding attestations before V1 is fully paused.
Which chains are affected
Circle currently lists 27 blockchains on its current CCTP network. However, Aptos, Noble, and Sui are marked as V1-only on the legacy network. A native route to or from those chains still depends on the old contracts unless an integrator uses a separate documented alternative. Circle has not said which exchanges, wallets, bridges, or apps still call V1, so the actual number of production integrations facing the cutoff is unclear.
The earlier deadline is important for teams that need uninterrupted service. Capacity begins shrinking at the end of October, not December. Anyone still on V1 should treat Oct. 31 as the real milestone.
In a November 2025 update, Circle said CCTP had processed more than $110 billion across 5.3 million transfers. Those cumulative totals include both V1 and V2 as of Nov. 14, 2025, so they show historical scale more than current exposure.
There is also a broader context. CryptoSlate’s earlier coverage of Noble described the wider V1 phase-out. With these dates, the integration-wide timetable is now set: burn limits start falling Oct. 31, and V1 contracts pause Dec. 1. Developers who have not started the migration may be on a shorter timeline than they think.
