Zcash is moving ahead with a network upgrade that puts a clear operational deadline on its oldest shielded payment pool. Users with coins in legacy Sprout addresses now face a specific choice: move funds before the NU7 upgrade, currently targeted for November 5, 2026, or risk leaving them unspendable indefinitely.
The reason is protocol mechanics, not speculation. Since launch, Sprout allowed private ZEC transfers using version four transactions, but newer upgrades shifted the standard to Sapling and later Orchard pools. The proposal for NU7, known as ZIP 2003, will remove support for version four transactions altogether. That means, once the upgrade activates, the network will no longer process Sprout spends, and any ZEC left in those addresses cannot be moved unless developers later add a separate recovery path.
For users, the urgency is now: ecosystem coverage has cited October 6 for testnet activation and October 20 as a decision checkpoint ahead of mainnet rollout. These coins are not erased or burned in protocol terms, but they do lose practical access for holders who miss the November deadline. The story here is operational, not speculative: a technical change is turning old wallet debt into a mandatory migration for anyone still holding funds in Sprout.