Circle has given developers still using the first version of its Cross-Chain Transfer Protocol a 95-day window to migrate before legacy contracts stop processing USDC transfers between chains. The deprecation timetable starts on October 31, 2026, when CCTP V1 burn limits begin to decrease. A burn limit caps how much USDC can be destroyed on one chain for reminting on another.
Circle will progressively reduce V1 transfer capacity through November, then pause the legacy contracts on December 1. Any integration still pointing to V1 at that date will no longer be able to move USDC across networks. The company said users will retain access to their funds during the phase-out and pending redemptions will remain available. Circle also said it will keep enough minting capacity available to complete outstanding attestations before V1 is fully paused.
The migration requires substantial code changes. CCTP V2, now branded simply as CCTP, uses different contract addresses, interfaces, and APIs and is incompatible with V1. Integrators must update their references to TokenMessenger, MessageTransmitter, and TokenMinter, 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 and handle applicable fees.
Circle's current supported-chain matrix lists 27 blockchains on the CCTP network. Aptos, Noble, and Sui are the only chains Circle 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. As historical context, Circle reported in November 2025 that CCTP had processed more than $110 billion across 5.3 million transfers, combining V1 and V2 activity as of Nov. 14, 2025.
