Zcash Targets Nov. 5 NU7 Upgrade With Block Times Cut to 25 Seconds

Key Points

• Zcash developers are targeting November 5 for the NU7 mainnet upgrade, subject to a final October 20 decision.
• NU7 would reduce targeted block spacing from 75 seconds to 25 seconds, making blocks three times more frequent.
• The upgrade will preserve Zcash’s halving schedule, disable version 4 transactions and introduce the Network Sustainability Mechanism.

Zcash developers have set November 5, 2026 as the target date for the NU7 network upgrade after engineering teams reached unanimous agreement on its planned scope and timetable. The upgrade would make a substantial change to network timing by reducing targeted block spacing from 75 seconds to 25 seconds. Before mainnet deployment, NU7 is scheduled to activate on the Zcash testnet on October 6. Developers will then evaluate its performance before making a final mainnet decision on October 20.

NU7 Cuts Block Spacing to 25 Seconds

The shorter block interval is based on ZIP-218, a proposal designed to reduce Zcash’s target block spacing by two-thirds. Moving from 75-second to 25-second blocks means the network would target approximately 2.4 blocks per minute instead of 0.8.

Faster blocks can reduce the waiting time for transaction confirmations and provide wallets and applications with more frequently updated blockchain data. However, three times as many blocks should not automatically be interpreted as three times the transaction capacity.

Zcash developer Sean Bowe confirmed that the ecosystem’s development organizations and relevant engineering teams had reached unanimous agreement on the planned NU7 package and timeline.

Testnet Comes Before November Launch

The NU7 rollout has several checkpoints before mainnet. Developers have set September 30 as the code-completion deadline. Features intended for NU7 should be implemented and ready for the testnet release by then.

The official Zcash testnet is scheduled to activate NU7 on October 6. Developers will observe the upgrade for approximately two weeks before making the final mainnet activation decision on October 20. The activation height is also expected to be established at that stage. That makes November 5 a target rather than an irreversible date. Significant problems discovered during testnet testing could still affect the schedule.

Halving Schedule Remains Intact

NU7 also addresses the future economics of ZEC. The planned Network Sustainability Mechanism (NSM) will preserve Zcash’s existing halving schedule, with reintroduction of previously removed supply beginning in February 2031.

Coinholder polling showed strong support for that approach. Approximately 98.9% of participating ZEC-weighted votes supported preserving halvings, while 99.9% backed the faster-block proposal.

NU7 will also disable version 4 transactions. That change effectively prevents additional spending from the legacy Sprout shielded pool because the newer v5 transaction format does not support Sprout.

Importantly, NU7 does not introduce a new transaction format. Bowe said wallets therefore should not face significant changes directly from the upgrade, although full nodes, indexers and block explorers may require updates.

ZEC Rallies Ahead of Upgrade

The technical roadmap arrives during a strong period for ZEC. Market data show ZEC surged about 20% on September 16, closing around $1,337, before climbing further to approximately $1,467 on September 17. The token was trading around $1,500 on September 18, although prices remain highly volatile.

The rally should not be attributed solely to NU7. ZEC has also benefited from broader interest in privacy-focused cryptocurrencies and other market-specific catalysts.

Conclusion

NU7 represents a significant infrastructure change for Zcash. Cutting targeted block spacing from 75 seconds to 25 seconds should provide faster block production, while the upgrade also addresses legacy transactions and the network’s longer-term sustainability mechanism.

The next critical date is October 6, when NU7 reaches the testnet. Developers will then decide on October 20 whether testing supports proceeding with the planned November 5 mainnet activation. Until that review is complete, November 5 should be treated as Zcash’s targeted launch date rather than a guaranteed deployment.