Zcash activates NU7 on testnet ahead of November mainnet target

Zcash has activated its NU7 network upgrade on testnet, with the scheduled activation block mined on Oct. 4. The upgrade introduces a reduced block spacing of 25 seconds, disables version 4 transactions, and adds a Network Sustainability Mechanism that diverts part of transaction fees into future block rewards, ahead of a targeted Nov. 5 mainnet rollout.

By AI Newsroom· Reviewed by Pranav, Founder & Editor-in-ChiefPublished 1 minute agoUpdated 1 minute ago0 views

Zcash activates NU7 on testnet ahead of November mainnet target

Why It Matters

Testnet activation gives developers and node operators several weeks to validate NU7 under real conditions and to evaluate potential impacts such as unspendable funds in the legacy Sprout shielded pool. The outcome of testnet testing will determine whether Zcash moves forward with mainnet activation in early November.

Key Facts

Testnet activation block: 4,465,026
Testnet activation time: Oct. 4 at 18:21:45 UTC
Planned mainnet decision date: Oct. 20
Targeted mainnet activation date: Nov. 5
Block spacing change: From 75 seconds to 25 seconds

Zcash has moved its NU7 network upgrade into live testing by activating the changes on testnet. According to the ZecBlock testnet explorer, block 4,465,026 — NU7's scheduled activation height — was mined on Oct. 4 at 18:21:45 UTC, and the Zcash project confirmed the upgrade's testnet status in a post on X.

NU7 includes several protocol adjustments intended to change block production cadence and fee allocation. The upgrade shortens the network's target block spacing from 75 seconds to 25 seconds, disables version 4 transactions, and implements a Network Sustainability Mechanism that channels a portion of transaction fees toward future block rewards.

One practical consequence of disabling version 4 transactions is that ZEC held in Zcash's legacy Sprout shielded pool could become unspendable after full activation unless users move those funds prior to the upgrade. The Zcash Foundation has urged testnet operators to run the release candidate and exercise NU7 in conditions that mirror mainnet activity so developers can observe real-world effects.

Zcash developers plan to review testnet results and decide whether to set the mainnet activation height at a meeting on Oct. 20. If they proceed, the team is targeting a Nov. 5 mainnet activation for NU7.