Circle has started a 95-day countdown for developers still using the first version of its Cross-Chain Transfer Protocol (CCTP), after which the legacy contracts will stop processing $USDC transfers.

CCTP is Circle's burn-and-mint mechanism for moving USDC between blockchains: tokens are destroyed on the source chain and reissued on the destination chain, an approach designed to avoid the wrapped, bridged asset variants that fragment stablecoin liquidity. The first version has been in production since 2023 and is used by exchanges, wallets, bridges and other apps to route USDC across networks.

Phase-out timeline

According to the company, CCTP V1 burn limits will start declining on Oct. 31. A burn limit caps how much $USDC can be burned on one chain for reminting on another. Circle plans to reduce those limits and transfer capacity through November, then pause the contracts on Dec. 1. At that point, any integration still pointing to V1 will no longer be able to move $USDC across chains.

The cutoff governs cross-chain routing. Circle's migration guide states that users will retain access to funds during the phase-out and that pending redemptions will remain available. Circle also said it will keep enough minting capacity available to complete outstanding attestations before V1 is fully paused. An attestation is Circle's signed approval for $USDC burned on a source chain to be minted on a destination chain.

Required code changes

The migration requires code changes. CCTP V2, now branded simply as CCTP, uses different contract addresses, interfaces and APIs and is incompatible with V1. Circle rolled out V2 in 2025 with an added fast-transfer option designed to settle in seconds, alongside standard settlement, which is why the migration now includes a choice between the two.

Integrators must point to the V2 versions of TokenMessenger, MessageTransmitter and TokenMinter, update their contract interfaces, and change calls to depositForBurn. The V2 function adds 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, choose standard or fast settlement where available, and handle applicable fees.

Teams that need uninterrupted service face an operational deadline earlier than Dec. 1. The Oct. 31 burn-limit reductions begin a November wind-down in which V1 capacity will progressively shrink.

Chain coverage and open questions

Circle's current supported-chain matrix lists 27 blockchains on the current CCTP network. Aptos is among the chains supported only by CCTP V1, alongside Noble and Sui, on Circle's legacy network. Those three are the only chains Circle currently labels as V1-only, and a native CCTP route to or from any of them still depends on the legacy network unless an integrator uses a separately documented alternative. The mix spans distinct technical ecosystems: Noble is the Cosmos-based chain that issues native USDC used across the IBC ecosystem, while Aptos and Sui run Move-based virtual machines rather than the EVM.

Circle did not identify which exchanges, wallets, bridges or apps continue to call the old contracts, leaving the number of named production integrations facing the cutoff undisclosed. The company's adoption figures offer historical scale rather than a measure of current exposure: in a November 2025 update, Circle said CCTP had processed more than $110 billion across 5.3 million transfers, cumulative totals that combined V1 and V2 as of Nov. 14, 2025.

CryptoSlate's earlier Noble coverage described the broader V1 phase-out. Circle's CCTP V1 deprecation dates now set the integration-wide timetable: capacity begins falling Oct. 31, and the V1 contracts pause on Dec. 1.

Source: CryptoSlate