Zcash's NU7 upgrade freezes ZEC left in its oldest privacy pool: who is affected

Zcash (ZEC) is switching on a network upgrade called NU7 at block 3,543,405, which Zcash's development organizations planned for around November 5, 2026. Once it is live, any ZEC still sitting in Sprout, the original privacy pool from Zcash's 2016 launch, can no longer be spent, even by owners who still hold the keys. [3] (opens in a new tab) [2] (opens in a new tab)

For most people who own ZEC today, the Sprout freeze does not touch their coins. It matters to anyone with a forgotten wallet from Zcash's early years.

What changes at NU7

Zcash keeps private balances in separate "shielded pools," each built on a different generation of its privacy technology. Sprout came first and was later replaced by the Sapling and Orchard pools, and more recently Ironwood. [6] (opens in a new tab) [1] (opens in a new tab) [3] (opens in a new tab)

The deployment spec, ZIP 259, says version 4 transactions become invalid once NU7 activates, while versions 5 and 6 stay valid. Sprout transfers can only be written in the version 4 format, so whatever is left in Sprout becomes unspendable. [2] (opens in a new tab)

ZIP 2003, the proposal behind the change, explains the reasoning. It calls Sprout "essentially unused" and says its older machinery still adds load and denial-of-service risk to the code every node runs to accept transactions. It also notes that when zcashd was deprecated just before the earlier NU6.3 upgrade, the last maintained wallet software with Sprout support went with it, although the network itself still accepts Sprout withdrawals until NU7 activates. [1] (opens in a new tab)

How much is still in Sprout

ZecStats' pool data showed 12,225.69 ZEC in Sprout on November 5, at block 3,542,654. A week earlier, on October 28, it showed 22,263.34. Most of the drop came on November 1, when the balance fell to about 13,170. [5] (opens in a new tab)

At US$1,318.49 per ZEC, CoinGecko's price at 6:06 a.m. ET on November 5, the remaining balance is worth about US$16.1 million. CoinDesk reported a similar figure of about $16 million. More withdrawals before activation would shrink it. [6] (opens in a new tab)

The pool balance is public, but it can't show who owns the coins or how much belongs to wallets whose keys are already lost.

When it happens

Activation is set by block height, not a clock time. The chain stood at block 3,542,654 in the ZecStats reading above, about 750 blocks short of activation. [5] (opens in a new tab) At the current 75-second target that points to Thursday night Eastern time, but block times vary. CoinDesk estimated activation near 9:30 p.m. ET Thursday, possibly slipping into early Friday. [6] (opens in a new tab)

This was not a surprise. Zcash organizations announced the November 5 target on the community forum in September, and Cointelegraph reported the Sprout warning on September 23. [4] (opens in a new tab) [7] (opens in a new tab)

Frozen, not burned

ZIP 2003 does not destroy Sprout coins. They stay counted in Zcash's issued supply, and the proposal leaves a theoretical door open to re-enable version 4 transactions or add some other way to retrieve them. It is blunt about the odds, though, warning that spending Sprout funds "may never be re-enabled." [1] (opens in a new tab)

What else NU7 changes

• Faster blocks: blocks are targeted every 25 seconds instead of every 75, so the average wait for a first confirmation falls by about two-thirds. Daily issuance stays the same because block rewards are divided by three. [3] (opens in a new tab)
• Fee reserve: 60% of each block's transaction fees is taken out of circulation and set aside; miners keep the other 40%. The 21 million ZEC cap and four-year halving schedule are unchanged. [3] (opens in a new tab)
• Node operators: the Foundation says every Mainnet node must upgrade before the activation block, or it will end up on a different chain. [3] (opens in a new tab)

What this means for you

• Check whether it applies: only funds in Sprout addresses are affected, and those addresses start with "zc". [8] (opens in a new tab) If you bought ZEC on an exchange and never moved it to an old "zc" address, the Sprout freeze is not about your coins.
• Old wallet from 2016–2018? Back up any old wallet file before touching it. A Zcash community forum recovery guide stresses the same point and warns against sharing your keys, wallet file or recovery words on any website, forum or chat. It points readers to a ZecHub recovery page. We have not tested any recovery tool, and with only hours left, a transfer may not confirm before the activation block. [8] (opens in a new tab) Moving coins out of Sprout also reveals the amount moved, because Sprout's pool balance is public. [1] (opens in a new tab)
• Expect recovery scams: after a deadline like this, fake "Sprout recovery" services tend to appear. Once NU7 is active the network itself rejects Sprout spends. Under those rules no person or service can move the coins for you; any way back would have to come from a network-wide upgrade, not a paid helper. Read our recovery scams guide before answering any offer.

This is a planned protocol change, not a hack. It is also a reminder that unused crypto in an old wallet can have deadlines attached. This is education, not financial advice.

Published November 5, 2026 by Dave McNaught. Educational content, not financial, legal or tax advice. Spot an error? Request a correction.

About the author

Dave McNaught

Dave McNaught has worked in IT since 1999 and founded All Business Technologies (ABT) in 2003, a Boston-area firm providing Managed IT, Cybersecurity, Managed AI, Web Design and App Development. He publishes The Crypto Guide.

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