Circle will begin throttling the legacy Cross-Chain Transfer Protocol (CCTP V1) on Saturday, October 31, starting a wind-down that ends on December 1, 2026, when V1 contracts stop operating. Applications still moving USDC through the legacy system have roughly one month to migrate to CCTP V2 or lose the ability to send the stablecoin across chains.

Burn limits to fall until the December 1 pause

CCTP links USDC across blockchains using a burn-and-mint design: the stablecoin is burned on the source chain and an equivalent amount is minted on the destination chain. Each mint must be cleared by an attestation signed by Circle, and a burn limit caps how much USDC the process can accept at any given time.

In a blog post on August 27, Circle said those limits would start to be lowered on October 31 and that performance would degrade over the following month until all legacy use is eliminated. Once the V1 contracts stop on December 1, integrations still tied to them will no longer be able to move USDC between chains.

Circle first warned about the move away from V1 on November 14, 2025, giving integrations more than a year to prepare. Noble, which will not receive CCTP V2, follows a separate schedule: new USDC minting on the chain was set to close on October 13, and the Noble USDC contract and all of its CCTP routes will stop working on January 12, 2027. Manual redemptions open a day later, on January 13, 2027.

Circle has now listed Sui on V2, and every V1 chain except Noble already uses the newer version of the protocol. That leaves the remaining migration work on the application side rather than with the networks themselves.

CCTP V2 adds three parameters to depositForBurn

CCTP V2 runs on its own contracts and APIs and cannot interoperate with V1. Developers need to point their code to the new interfaces, including TokenMessengerV2 and MessageTransmitterV2. The V2 depositForBurn function adds three extra parameters: a destination caller, a maximum fee, and a minimum finality threshold.

Rather than pulling message bytes from an on-chain transaction and hashing them, integrations now request them from a V2 messages API using the transaction hash. Functions such as replaceDepositForBurn are no longer available in V2. Circle's Arc App Kits handle contract addresses and attestation polling automatically, lifting that burden from developers.

V2 introduces Standard and Fast Transfer modes and supports 31 blockchains. Programmable hooks let an application trigger an automatic action on the destination chain when USDC arrives. Fast Transfer fees are based on the source chain, whereas transfers under V1 carried no fee.

Circle said minter allowances will exceed pending attestations so that in-flight transfers can be settled before the December 1 pause.

CCTP has faced legal scrutiny before

In April, a Drift Protocol investor filed suit against Circle in a Massachusetts district court in connection with the $280 million Drift exploit, Cryptopolitan reported. The class action claims Circle failed to freeze around $230 million of USDC that North Korean hackers channeled through CCTP. CEO Jeremy Allaire said Circle freezes wallets at the direction of law enforcement or courts and should not act as a digital vigilante.

Separately, Circle launched its Arc layer-1 blockchain on mainnet in September, with validators including BlackRock, Visa, Mastercard and DTCC — new infrastructure arriving even as the company retires its legacy cross-chain rails.