Zcash activated its NU7 upgrade on a public testnet at block 4,465,026, cutting the target block interval from 75 to 25 seconds. Coming earlier than initially expected, the change reshapes the network’s latency, shielded transaction throughput and fee economics, just weeks before a mainnet deployment targeted for November 5, 2026.
🔑 Key Takeaways
- NU7 activated on a public testnet at block 4,465,026, reducing the target block interval from 75 to 25 seconds
- Orchard capacity for two-action transactions rises from about 2.9 to 6.6 transactions per second
- The Network Sustainability Mechanism redirects 60% of fees into a mining reserve
- Sprout v4 transactions are disabled and the existing halving schedule is preserved
- The holder vote gathered 2.4 million ZEC with approximately 99.9% approval for 25-second blocks
An earlier-than-expected testnet activation
NU7 activated at block 4,465,026 on the new public testnet, ahead of the initial estimate of around October 6, 2026. The Zakura team shipped its implementation on October 1, 2026, followed the next day by the Zcash Foundation with a test build of Zebra. On October 2, 2026, Zebra 7.0.0-rc.0 was published as a release candidate. The previous testnet was retired, and both major node programs now support the trial.
The interval change is governed by ZIP 218 and forms the technical centerpiece of the upgrade. A service waiting for three confirmations would see its target wait fall from roughly 225 seconds to 75 seconds, assuming confirmation policy remains unchanged. Actual block times will continue to vary with network propagation and proof-of-work variability.
Throughput, latency and Orchard caps
ZIP 218 authors model a near-tripling of throughput for specific shielded operations. The maximum Orchard capacity for two-action transactions would rise from about 2.9 to 6.6 transactions per second, bounded by new per-block caps of up to 330 Orchard actions.
Counter-intuitively, the maximum shielded sync bandwidth is modeled to drop by roughly 37%, a consequence of tighter caps that limit the size of each useful block. Separately, the Zakura developers reported that their open-source cryptographic toolkit cut private transaction construction from more than three seconds to under 200 milliseconds in some tests, an improvement wallets can adopt without waiting for a coordinated network upgrade.
“Zakura’s open-source cryptographic toolkit cuts private transaction construction from more than three seconds to under 200 milliseconds in some tests.”
Zakura developers
NSM: 60% of fees to a reserve
NU7 also introduces the Network Sustainability Mechanism (NSM), defined by ZIP 235 and ZIP 237. Under the upgrade, 60% of transaction fees are redirected to a reserve that funds future mining rewards, while miners receive 40% of fees and the remaining 60% is removed from circulation. The goal is to support miner revenue as block rewards decline through successive halvings, without breaching Zcash’s 21 million ZEC supply cap.
| Parameter | Before NU7 | After NU7 |
|---|---|---|
| Target block interval | 75 seconds | 25 seconds |
| Three confirmations (target) | ~225 seconds | ~75 seconds |
| Orchard capacity (two actions) | ~2.9 tx/s | ~6.6 tx/s |
| Orchard cap per block | Variable | Up to 330 actions |
| Block subsidy | 0.78125 ZEC | 0.26041666 ZEC |
| Halving interval | 1.68M blocks | 5.04M blocks |
| Fee share to miners | 100% | 40% |
| Fee share to NSM reserve | 0% | 60% |
The per-block subsidy is cut to one third, preserving the global emission schedule: blocks three times more frequent do not triple new coin creation. The halving interval rises from 1.68 million to 5.04 million blocks.
Sprout disabled and the holder vote
NU7 disables Sprout v4 transactions, Zcash’s oldest private payment system. Sprout deposits were already disabled, the reserve holds fewer than 23,000 ZEC and these transactions represent less than 0.1% of volume. Affected holders must move their funds before mainnet activation to retain the ability to spend them through the existing system. NU7 introduces no new transaction formats.
The holder vote gathered approximately 2.4 million ZEC, or about 66% of Ironwood eligible balances at the snapshot taken at block 3,459,350 on August 24. The poll closed on September 14 at 19:00 UTC. Roughly 99.9% of voting ZEC backed the 25-second interval, about 98.9% supported preserving the halvings, and around 96.6% endorsed a February 2031 start for NSM reissuance. A parallel Zcash Community Advisory Panel survey, with 135 ballots from 198 members, remained split on smoothed issuance (57 in favor, 54 against).
Built by Valar Group, the voting system ran on a dedicated chain and relied on homomorphic encryption. A distributed election authority of at least ten validators held key shares, with each vote split into 16 unlinkable parts to preserve balance confidentiality. Five groups coordinated the operation: Project Tachyon, Valar Group, the Zcash Foundation, Zodl and Shielded Labs.
Market context and the mainnet timeline
The schedule calls for a review of test results and a mainnet activation decision on October 20, 2026, with a target kept at November 5, 2026. No activation block is yet specified. On the public testnet, a third adjusted halving is expected at block 4,497,948 and NSM reissuance begins at block 7,305,222.
“Zcash is a private complement to Bitcoin.”
Matt Huang, co-founder of Paradigm
In September 2026, Paradigm co-founder Matt Huang revealed that the firm had bought ZEC, triggering a sharp rally. ZEC climbed roughly 20% in 24 hours, reaching levels near $1,521, an effective new all-time high. On September 16, CoinGecko placed ZEC near $1,146 with a market cap close to $19.4 billion. By September 28, the 24-hour move was 3.8%, extending a 132% monthly rally. Grayscale filed with the US SEC a 3-for-1 share split for its Zcash product on NYSE Arca, ticker ZCSH, after a gain of nearly 2,800% over the period. Glassnode data showed the privacy-coin sector trading 213% above its level at Bitcoin’s October 2025 peak.
Conclusion
With NU7, Zcash reconfigures three core protocol variables at once: block issuance cadence, fee structure and the map of its shielded pools. A 25-second interval brings the network closer to modern DeFi standards without accelerating monetary creation, while the NSM prepares the ground for post-halving cycles. The convergence of institutional-driven market momentum and tight technical coordination between the project’s main actors creates a strategic observation window for the coming months.
The main risk remains operational: a mainnet bug, frictions in migrating remaining Sprout balances or community pushback against an earlier NSM start could delay deployment. Conversely, a smooth activation on November 5, 2026 would reinforce the network’s technical credibility and support the price momentum seen since the summer. The October 20, 2026 decision is, in that sense, the next catalyst to watch.
Sources
This article is published for informational and educational purposes only. It does not constitute investment advice. Do your own research (DYOR) before making any decision.
