Zcash activated its NU7 network upgrade on public testnet at block height 4,465,026 on October 4, 2026, two days before the October 6, 2026 Zcash Foundation's projected date
The Zcash NU7 upgrade aims to cut the target block spacing from 75 seconds to 25 seconds
The Zcash NU7 upgrade integrates a Network Sustainability Mechanism, which redirects 60% of transaction fees to a reserve for future mining rewards while leaving miners with 40%
Zcash developers plan to review the NU7 testnet results and make a final decision on NU7's mainnet activation and its block height on October 20, 2026
The target date for the Zcash NU7 mainnet activation is November 5, 2026, though no mainnet activation block height has been set yet
The Zcash NU7 upgrade disables version 4 transactions and retires the Sprout shielded pool, Zcash's oldest privacy system
Zcash developers and forum participants warned that ZEC funds left in the Sprout shielded pool must be moved before NU7's mainnet activation or they will become unspendable
To preserve the ZEC issuance schedule with faster blocks under Zcash's NU7 upgrade, the scheduled reward per block is reduced to one-third, keeping the daily amount of new ZEC the same
The Zcash Foundation stated that Zcash's NU7 block time reduction aims to resolve transaction waiting obstacles for point-of-sale merchants, exchange deposits, and cross-chain bridges
The Zcash NU7 public testnet trial uses valueless coins to allow developers and infrastructure operators to rehearse the NU7 upgrade and validate their software
Zcash coinholders voted in September 2026 to begin paying out the NU7 upgrade's Network Sustainability Mechanism reserve through block rewards starting in February 2031
Zcash is justified in making unmoved Sprout pool funds unspendable
Redirecting 60% of Zcash transaction fees to a reserve unfairly penalizes current miners
Reducing Zcash's block time to 25 seconds is necessary for commercial viability
The two-week window between Zcash's NU7 decision and mainnet launch is too short
