Zcash Sets November 5 Target for NU7 Upgrade with 25-Second Blocks

The upgrade reduces target block times from 75 seconds to 25 seconds, a move overwhelmingly supported by 99.9% of the ZEC participating in recent governance polls. To manage the increased synchronization demands, the update includes new limits on shielded transaction activity within specific pools. While existing version 5 and version 6 transaction formats remain valid, the upgrade marks the end of the legacy Sprout system. Coins currently held in the original 2016-era Sprout pool will become unspendable once the network reaches the activation block, requiring holders to migrate funds to supported pools beforehand.

Beyond speed improvements, NU7 introduces the Network Sustainability Mechanism. This feature temporarily removes 60% of transaction fees from circulation, holding them in a tracked balance for future reissuance starting in 2031 at block 8,939,664. Although the activation height is confirmed by developers Sean Bowe, ValarDragon, and str4d, the final integration into the network’s deployment specification remains pending. Node operators must update their software prior to the activation block to ensure compatibility with the new consensus rules, as outdated software may result in following an incompatible chain.