Circle cuts legacy USDC limits before Dec 1 CCTP pause

Circle will begin reducing burn limits for its legacy Cross-Chain Transfer Protocol (CCTP V1) on Oct. 31, 2026, preceding a scheduled contract pause on Dec. 1, 2026. As of Oct. 29, 2026, applications relying on the legacy protocol face tightening USDC transfer capacity in the coming weeks.

Staged reduction in transfer capacity

The wind-down first reduces how much USDC can enter the cross-chain process. Circle’s schedule mandates lower burn limits starting Oct. 31, followed by a gradual performance decline. Once contracts pause on Dec. 1, integrations using CCTP V1 will stop transferring USDC between blockchains.

CCTP burns USDC on a source blockchain and mints it on a destination chain. A burn limit caps the amount entering this process, while an attestation serves as Circle’s signed approval for minting. The migration guide outlines progressively tighter message limits until no new burns can be initiated, aiming for zero transfer volume before the full pause.

This phase-out affects an application’s ability to route transfers through November and the final cutoff. Circle announced the move from V1 on Nov. 14, 2025, and published the October-to-December timetable on Aug. 27, 2026.

Migration to incompatible V2 system

Applications must update contract calls and APIs because the new system, branded as CCTP, is incompatible with V1. Circle’s guide identifies new addresses and interfaces, including TokenMessengerV2 and MessageTransmitterV2. The TokenMessengerV2 interface’s depositForBurn function adds parameters for the permitted destination caller, maximum fee, and minimum finality threshold.

The attestation workflow also changes. Rather than extracting and hashing message bytes from an onchain transaction, integrations can use the V2 messages endpoint with the transaction hash to retrieve the message and attestation. V2 also introduces Standard and Fast Transfer modes and programmable hooks. Fast Transfer uses a variable fee based on the source chain, requiring migration to account for these costs.

Some functions are removed, including replaceDepositForBurn. Circle also offers Arc App Kits to abstract contract-address, interface, and attestation work for developers.

Pending redemptions remain available

Pending redemptions will remain available throughout the phase-out. Circle will maintain minting allowances above the total of pending attestations to ensure redemptions are processed before the Dec. 1, 2026, pause. This separates the completion of outstanding transfers from the allowance for new activity.