Zcash NU7 Upgrade Goes Live on Testnet Ahead of November Launch

Zcash has moved its next major network upgrade into live testing, activating NU7 on testnet ahead of a planned mainnet launch in November.

The upgrade reached its scheduled testnet activation point at block 4,465,026 on Oct. 4 at 18:21:45 UTC, according to the Zcash testnet block explorer ZecBlock. Zcash later confirmed that NU7 was active on testnet.

NU7 brings several protocol changes, with one of the biggest being a sharp reduction in Zcash’s target block time. The upgrade is designed to cut block spacing from 75 seconds to 25 seconds, allowing transactions to be processed through new blocks more frequently.

The upgrade will also remove support for version 4 transactions and introduce a Network Sustainability Mechanism. Under the new system, a portion of transaction fees will be redirected toward future block rewards as part of changes to the network’s long-term funding model.

Users holding ZEC in the legacy Sprout shielded pool face an additional deadline. Once NU7 is fully activated, version 4 transaction support will be disabled, meaning funds remaining in the old Sprout pool could become unspendable unless they are moved beforehand.

The Zcash Foundation has encouraged testnet operators to run the NU7 release candidate under real network conditions. The testing period is intended to give developers and other participants time to identify potential issues before the upgrade reaches the main Zcash network.

Developers are expected to review the testnet results and make a final decision on mainnet activation on Oct. 20. The activation block height will also be determined at that time.

For now, Zcash is targeting Nov. 5 for the NU7 mainnet rollout, giving the network several weeks to test the changes before the planned launch.