Cross-chain USDC integrations have a deadline, not just a version upgrade. Circle says CCTP V1 (Legacy) deprecation starts October 31, 2026, with contracts paused on December 1. Burn limits will tighten during the transition, so legacy routes may degrade before they stop. CCTP V2 uses separate contracts and APIs, making this a breaking migration rather than a drop-in update. Circle’s docs say V2 adds Fast Transfer, Hooks, and wider chain support. Teams should audit contract addresses, API calls, and pending-redemption flows now; this is infrastructure hygiene, not a signal about USDC demand or price.