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

Circle’s CCTP V1 deprecation gives developers still using the first version of its Cross-Chain Transfer Protocol (CCTP) 95 days to migrate before the legacy contracts stop processing $USDC transfers.

The company said CCTP V1 burn limits will begin falling on Oct. 31. A burn limit caps how much $USDC can be destroyed 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. Any integration still pointing to V1 at that point will no longer move $USDC across chains.

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

CCTP V1 deprecation: code changes and exposed routes

The migration requires code changes. CCTP V2, now branded simply as CCTP, uses different contract addresses, interfaces and APIs and is incompatible with V1.

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 earlier operational deadline than Dec. 1. The Oct. 31 burn-limit cuts begin a November wind-down in which V1 capacity will progressively shrink.

Circle’s current supported-chain matrix lists 27 blockchains on the current CCTP network. Aptos is listed among the chains supported only by CCTP V1, alongside Noble and Sui, on Circle’s legacy network.

Aptos, Noble and Sui are the only chains Circle currently labels as V1-only. A native CCTP route to or from any of them still depends on the legacy network unless an integrator uses a separately documented alternative. 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.

Circle’s adoption figures offer historical scale rather than a measure of current exposure. In a November 2025 update, the company said CCTP had processed more than $110 billion across 5.3 million transfers. Those cumulative totals 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 V1 contracts pause Dec. 1.