Zcash targets November for NU7 mainnet upgrade with 25-second blocks

Zcash developers are targeting Nov. 5 for NU7 mainnet activation after organizations and engineering teams reached “unanimous agreement” on its contents and estimated timeline. 

On Thursday, Zcash developer Sean Bowe said the upgrade is scheduled to activate on the testnet on Oct. 6. A final decision on the mainnet upgrade and its activation height is scheduled for Oct. 20, after an assessment of NU7’s testnet performance. 

The upgrade would reduce Zcash’s target block spacing from 75 seconds to 25 seconds, disabling version 4 transactions and integrating the Network Sustainability Mechanism (NSM). The chosen NSM configuration would preserve Zcash’s halving schedule, with the reintroduction of previously removed supply beginning in February 2031. 

Bowe said NU7 would not introduce new transaction formats and should not significantly affect wallets. He said full nodes, indexers and block explorers may require adjustments. 

On Wednesday, ZEC holders overwhelmingly backed the shorter block interval and preserving the halving schedule. 98.9% supported keeping halvings, while 99.9% of the Zcash (ZEC)-weighted vote supported the faster-block proposal. 

The timeline came amid a recent surge in ZEC’s price. On Thursday, ZEC rose about 20% over 24 hours as privacy coins substantially outperformed the wider market. Glassnode data showed that the sector was 213% above its level at Bitcoin’s October 2025 peak, while a basket excluding ZEC was up about 85% over the past year.