Zcash Sets NU7 Mainnet Block, Sprout Funds Face Cutoff

NU7 mainnet block replaces a provisional timetable

Zakura’s rollout dashboard lists mainnet as pending at block 3,543,405, with November 5 as the approximate date. The block height controls activation; variations in mining mean the calendar estimate can shift.

The dashboard’s active network measurements concern public testnet. Its displayed observation is a saved October 21 snapshot, explicitly labeled as such when live verification is unavailable. Neither an advancing testnet nor its measured intervals prove that mainnet has switched rules.

The v1.7.0-rc2 release notes show Zakura has incorporated the mainnet height. GitHub labels the build a pre-release. That establishes implementation progress, rather than universal readiness across node software, wallets and exchanges.

The distinction matters for operators comparing version numbers. A release that supports NU7 on testnet does not necessarily contain the final mainnet schedule. Each operator needs to verify the relevant network and activation constants in its chosen software.

The deployment specification also waives the usual requirement that activation come after unsupported software’s deprecation height, alongside the recommended three-month release lead time. Old nodes may remain running on a pre-NU7 branch, making a running process insufficient evidence of compatibility.

Sprout spending stops at the NU7 cutoff

The most direct balance consequence concerns Sprout, Zcash’s oldest shielded pool. ZIP 2003 explains that Sprout transfers require version 4 transactions, which become invalid from NU7 onward.

Funds left there will therefore become unspendable under the new consensus rules. The specification does not characterize them as stolen or permanently destroyed. It leaves a theoretical possibility of a future recovery facility, while warning that spending may never be re-enabled.

For holders, that makes the period before activation the relevant window to resolve old Sprout balances. Recovery can already be difficult: ZIP 2003 says zcashd’s deprecation removed the only maintained software that had provided Sprout wallet functionality.

The restriction also reaches beyond Sprout. Version 4 transactions containing only transparent or Sapling transfers will be rejected too. Wallets and transaction services must construct supported formats, including when handling saved or offline-signed transactions intended for later submission.

This is a transaction-compatibility change, not a universal requirement to exchange ZEC for a replacement token. Modern balances and older Sprout funds face different operational questions, so provider guidance needs to identify the actual wallet and transaction path affected.

The specification also notes a privacy tradeoff when leaving Sprout: transferred amounts change publicly visible pool balances, and timing can aid correlation. A compressed exit window is therefore more than a software-support issue for users of the older privacy system.

25-second blocks change payments and mining fees

ZIP 218 reduces target spacing from 75 seconds to 25 seconds. A service retaining a three-confirmation requirement would have a target wait near 75 seconds instead of 225, before processing delays. Those are illustrative averages, not guaranteed settlement times.

Exchanges can revise confirmation requirements, and applications have their own processing delays. Faster blocks alone do not establish a threefold improvement in every deposit or checkout experience. Services will need to communicate their actual policies around activation.

The scheduled subsidy per block falls to approximately one-third, offsetting the increased block frequency. NU7 retains the halving-based issuance structure; it does not triple daily scheduled issuance. Rounding also leaves eventual issuance slightly below the existing cap.

ZIP 235’s fee rule allocates 40% of aggregate transaction fees to miners and removes 60% from circulation for the Network Sustainability Mechanism. The removed share is intended for later algorithmic reissuance, rather than a permanent burn or a discretionary treasury payout.

The NSM specification places mainnet reissuance at block 8,939,664, well after NU7 activation. Its balance is public consensus state, not a wallet whose manager can distribute funds at will. Collection and eventual reissuance are separate events.

These changes are also separate from the proposed quantum-privacy protection for Zcash swaps. A scheduled consensus upgrade does not establish deployment of that distinct wallet design.

Alternative.me’s Fear & Greed Index showed 68 on October 22, up from 63, with both readings in Greed. The broader-market gauge does not measure NU7 readiness.

Source: Alternative.me, checked October 22.

As of October 22 at 00:07 UTC, the reviewed dashboard still marked mainnet pending. The next checkpoints are compatible production releases, wallet and exchange service notices, and the chain reaching block 3,543,405. A complete cross-provider readiness assessment was not available in the reviewed sources.