NU7 Goes Live on Testnet

Zcash has activated its NU7 network upgrade on the public testnet, moving the next major protocol overhaul into live testing roughly a month before its planned mainnet debut. According to the Zcash testnet block explorer ZecBlock, block 4,465,026, NU7's scheduled activation point, was mined on Oct. 4 at 18:21:45 UTC. The activation block arrived earlier than the roughly Oct. 6 timing developers had previously estimated.

NU7 is Zcash's next network upgrade and seeks to reduce the network's target block spacing from 75 seconds to 25 seconds. The upgrade also disables version 4 transactions and integrates a Network Sustainability Mechanism that redirects part of transaction fees into future block rewards.

Producing blocks more frequently could shorten the wait for a merchant to accept a payment or an exchange to credit a deposit. A service waiting for three confirmations would face a targeted wait of about 75 seconds instead of 225, if it kept its confirmation requirement unchanged.

What Changes and What Is at Risk

The upgrade allocates 40% of transaction fees to miners and 60% to a reserve for future rewards, while maintaining the coin issuance schedule.

Disabling version 4 transactions would leave $ZEC held in Zcash's legacy Sprout shielded pool unspendable unless users move the funds before NU7 fully activates. Holders with funds in the Sprout pool should act well ahead of the November 5 target date to avoid losing access.

The Zcash Foundation said that testnet operators should use the release candidate to test NU7 "under real conditions." The testnet phase allows developers to assess the upgrade before deciding whether to proceed with mainnet activation. Developers are scheduled to review the testnet results on Oct. 20 before deciding whether to proceed with mainnet activation and setting the final activation height.

Zcash is set to launch its NU7 network upgrade on November 5, 2026, representing a major blockchain upgrade for the privacy-focused project.

Sources:
CoinDesk: Zcash's 25-Second Blocks Go Live on Public Testnet
FXStreet: Zcash Activates NU7 on Testnet Ahead of November Mainnet Target
Crypto News: Zcash NU7 Goes Live on Testnet With 25-Second Blocks