Zcash NU7 Upgrade Activates November 5 With 25-Second Block Time

The Zcash NU7 upgrade activates on mainnet at block height 3,543,405, targeted for November 5, 2026. The change reduces target block time from 75 seconds to 25 seconds and implements several adjustments defined in ZIP 259.

Zcash NU7 Upgrade Activation Schedule and Technical Changes

Activation occurs at a fixed block height rather than a clock time. Current mainnet height sits in the low 3,540,000 range as of November 3, 2026, placing the upgrade roughly two days ahead. Testnet reached its activation height of 4,465,026 on October 4, 2026, allowing developers to verify behavior before mainnet.

The upgrade merges changes from ZIP 218, ZIP 235, ZIP 237, and ZIP 2003. Block subsidy per block drops by approximately two-thirds to maintain daily ZEC issuance near 1,800 ZEC. Difficulty adjustment windows widen from 17 blocks to 102 blocks. Version 4 transactions are disabled, rendering remaining Sprout pool funds permanently unspendable after activation.

Transaction fee mechanics shift as well. Sixty percent of fees move into a reserve while miners retain 40 percent. The Network Sustainability Mechanism begins reissuance of the reserve to miners around February 2031 at block 8,939,664. Shielded action limits are introduced at both pool and global levels.

Network Effects of the Zcash Block Time Reduction

First confirmation time falls to roughly 25 seconds after the upgrade. Three-confirmation settlement completes in about 75 seconds instead of the prior 3.75 minutes. Infrastructure operators including explorers and indexers received advance notice to update block time assumptions and difficulty calculations.

Node software support comes from Zebra 7.0.0 and updated Zakura releases. The zcashd client is deprecated for this upgrade. Most wallets require no changes, though users holding Sprout funds must migrate assets beforehand. Approximately 22,263 ZEC remained in the Sprout pool in late October 2026 and will stay in the issued supply without becoming spendable.

Daily issuance stays constant while the halving schedule and 21 million cap remain unchanged. Coinholder polls conducted earlier in 2026 showed 99.9 percent support for the 25-second block target and 98.9 percent support for preserving the halving timeline. Miners and pools such as F2Pool have published operational notices ahead of the height.

Post-Activation Monitoring and Market Context

Block explorers will display the exact activation block once reached. Observers expect faster confirmation visibility and adjusted fee market dynamics immediately afterward. The upgrade follows unanimous agreement among Zcash Foundation, Zebra, Zakura, Tachyon, and Valar teams after testnet data review.

No new transaction formats are introduced. Existing shielded and transparent transaction types continue without modification. Participants tracking ZEC blockchain performance can monitor height progression through public dashboards to determine precise timing within a narrow window around November 5 or early November 6.