Circle Sets 95-Day Countdown for Legacy USDC Cross-Chain Transfer Protocol Shutdown

Circle’s decision to sunset CCTP V1 gives developers still operating on the first version of its Cross-Chain Transfer Protocol a 95-day window to migrate before the legacy contracts cease processing USDC transfers entirely.

According to the company, CCTP V1 burn limits will begin declining on October 31. A burn limit restricts the volume of USDC that can be destroyed on one blockchain for reminting on another. Circle intends to gradually reduce these limits and transfer capacity throughout November, before pausing the contracts on December 1. At that point, any integration still routing through V1 will be unable to move USDC across chains.

The cutoff applies to cross-chain routing specifically. Circle’s migration documentation confirms that users will retain access to their funds throughout the phase-out period, and pending redemptions will remain available. An attestation represents Circle’s signed authorization for USDC burned on a source chain to be minted on a destination chain. The company has stated it will maintain sufficient minting capacity to complete outstanding attestations before V1 is fully paused.

CCTP V1 deprecation: code changes and exposed routes

The migration demands substantive code changes. CCTP V2, now marketed simply as CCTP, operates with different contract addresses, interfaces, and APIs and is not backward compatible with V1.

Integrators must redirect to the V2 versions of TokenMessenger, MessageTransmitter, and TokenMinter, update their contract interfaces, and modify calls to depositForBurn. The V2 function introduces additional parameters for the permitted destination caller, maximum fee, and minimum finality threshold. Developers must also replace legacy attestation calls with the /v2/messages/{sourceDomainId} flow, select between standard and fast settlement options where available, and account for applicable fees.

Organizations requiring uninterrupted service face an earlier operational deadline than December 1. The October 31 burn-limit reductions initiate a November wind-down during which V1 capacity will progressively contract.

Circle’s current supported-chain matrix identifies 27 blockchains on the active CCTP network. Aptos appears among the chains supported exclusively by CCTP V1, alongside Noble and Sui, on Circle’s legacy network.

Aptos, Noble, and Sui represent the only chains Circle currently designates as V1-only. A native CCTP route connecting to or from any of these networks continues to depend on the legacy infrastructure unless an integrator employs a separately documented alternative. Circle has not disclosed which exchanges, wallets, bridges, or applications continue to invoke the old contracts, leaving the count of named production integrations facing the cutoff unknown.

Circle’s published adoption metrics provide historical context rather than a snapshot of current exposure. In a November 2025 update, the company reported that CCTP had processed more than $110 billion across 5.3 million transfers. Those cumulative figures encompassed both V1 and V2 activity as of November 14, 2025.

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