When Zcash’s planned NU7 upgrade goes live, the old Sprout privacy system will shut down, and coins remaining in it will become unspendable.
According to CoinDesk, developer Sean Bowe proposed activating the upgrade at block 3,543,405. The Zakura node software’s upgrade dashboard lists this level as the planned mainnet transition point, which is expected to fall around November 5.
Which Zcash holders need to take action?
The warning applies to users who still hold coins in Sprout, Zcash’s original privacy system. Since NU7 will shut down the system entirely, those coins need to be moved out of Sprout before the upgrade activates.
The risk is not a transaction freeze affecting all ZEC balances; it concerns coins left in the old system. The key distinction for users, therefore, is whether their assets are held in Sprout.
The November 5 date is not yet final
Although Bowe’s proposal has received two approvals, it had not yet been added to the deployment documents as of Wednesday, October 21, at 11:00 a.m. TRT. The documents still showed the mainnet activation height as undetermined. Node software also needs to include the selected block number for the upgrade to be implemented.
Therefore, around November 5 is emerging as the planned transition time; for Sprout balances, the actual deadline will be the block at which NU7 goes live.
Changes to speed and fees, too
We previously covered Zcash’s rally and NU7’s speed target. The upgrade will reduce the time between blocks from 75 seconds to 25 seconds. For an exchange that waits for three confirmations, this means the wait would drop from about four minutes to one minute and 15 seconds, assuming the same confirmation requirement.
NU7 will also temporarily remove from circulation 60% of the transaction fees collected in each block. These coins are planned to be returned to miners starting around February 2031, while the current schedule for halving mining rewards will remain in place.
Not investment advice.