TL;DR
Zcash will activate the NU7 upgrade around November 5, reducing block times from 75 to 25 seconds.
The upgrade will introduce a mechanism that reserves 60% of transaction fees to fund future block rewards.
Validators will need to upgrade their nodes to Zebra 7.0.0 before activation. Transactions using the legacy Sprout protocol will also be disabled.
Zcash ** is preparing to activate Network Upgrade 7 (NU7), an upgrade that will reduce block times from 75 to 25 seconds** and change how the network distributes transaction fees .
Activation is expected around November 5 , when the blockchain reaches block 3,543,405 . The change will allow transactions to receive their first confirmation approximately three times faster , without changing the daily amount of ZEC issued.
The upgrade will also disable new transactions through Sprout , one of Zcash’s oldest privacy protocols. Users who still hold funds in that system will need to move them to Sapling before activation.
Zcash’s Blossom upgrade (2019) halved block time from 150 to 75 seconds
This reduced the 500-block Sprout to Sapling pool migration interval from 20.8 to 10.4 hours.
Network Upgrade 7 (November 5th) reduces block time again from 75 to 25 seconds & disables Sprout… pic.twitter.com/PD5UEQ9poO
— Zcash (@Zcash) October 25, 2026
Zcash to Cut Block Times Without Increasing ZEC Issuance
The reduction in block intervals is defined in ZIP 218 . Zcash currently produces a block every 75 seconds on average, a period NU7 will shorten to 25 seconds .
The network previously changed this parameter in 2019 through the Blossom upgrade, which reduced block times from 150 to 75 seconds.
NU7 will also introduce new restrictions on activity within the Orchard, Ironwood , and Sapling protocols, designed to protect light wallets against transactions intended to overwhelm the network.
According to the technical specifications, the changes will increase Orchard’s capacity from 2.9 to 6.6 transactions per second and reduce the maximum bandwidth that a spam attack could demand during synchronization by approximately 37% .
NU7 to Introduce New Rules for Fees and Rewards
Another change is the Network Sustainability Mechanism , designed to reserve a portion of transaction fees for future rewards to block producers.
Under ZIP 235 , 60% of each block’s transaction fees will be temporarily removed from circulation and placed in a reserve. The remaining 40% will continue going to miners .
The redistribution of those funds will begin later, at block 8,939,664 , under the rules established in ZIP 237 and ZIP 259. The halving schedule and maximum supply of 21 million ZEC will remain unchanged .
To prepare for activation, Zcash released Zebra 7.0.0 on October 22, the first stable version supporting NU7 on mainnet.
All operators must install it before the network reaches the scheduled activation height. Zebra 6.4.x versions will stop running several days before activation to prevent nodes from continuing to operate under the previous consensus rules.
