Zcash Foundation releases first NU7 candidate as Zebra testnet date nears
In brief
- Zebra 7.0.0-rc.0 is the first release candidate for NU7, Zcash's next network upgrade.
- NU7 testnet activation is set at block 4,465,026, expected around October 6, 2026.
- NU7 mainnet activation height is due to be set on October 20, 2026.
- NU7 would cut target block spacing from 75 seconds to 25 seconds under ZIP 218.
Two dates in October
NU7 is now code-complete in Zebra, per the foundation's announcement. That doesn't put it on mainnet. The second date to watch is October 20, 2026, when U.Today reported that the mainnet activation height will be set (that's the day the height gets chosen, not the day the upgrade switches on).
Testnet comes first.
A social media post embedded in U.Today's report spelled out the ask for node runners:
"Testnet operators should upgrade before then"
Faster blocks under ZIP 218
A Zcash user currently waits 75 seconds on average for a first confirmation, which U.Today described as an obstacle at points of sale, for exchange deposits and for cross-chain bridges. Under ZIP 218, NU7 cuts the target block spacing to 25 seconds, so the average wait for a first confirmation drops to 25 seconds too. Daily ZEC issuance doesn't change.
Fees, a reserve and spam limits
Block rewards drop with each halving, and the network is expected to eventually rely on fees to fund its security. NU7's response is a sustainability mechanism that recycles part of every transaction fee into future block rewards, according to the foundation. Under ZIP 235, 60% of each block's transaction fees would be withdrawn from circulation into a reserve, while miners keep the remaining 40%. ZIP 237 then has each block reissue a small, predictable portion of that reserve on top of its normal reward. The four-year halving schedule and the 21 million ZEC supply cap stay as they are.
The upgrade also adds per-block limits on shielded transactions, intended to protect wallets from spam: 330 Orchard or Ironwood operations, 300 Sapling inputs and outputs, a shared budget of 330 across pools, and no new Sprout JoinSplits.
None of it is live on mainnet yet (it's all tied to an activation height that hasn't been set).
Frequently asked questions
When does Zcash's NU7 upgrade activate?
NU7 testnet activation is set at block height 4,465,026, expected around October 6, 2026. The mainnet activation height is scheduled to be set on October 20, 2026, according to U.Today. That is the date the height gets chosen, not a mainnet activation date.
How will NU7 change Zcash block times?
Under ZIP 218, NU7 cuts the target block spacing from 75 seconds to 25 seconds, so the average wait for a first confirmation drops to 25 seconds. The amount of ZEC issued per day stays the same.
How does NU7's fee reserve mechanism work?
Under ZIP 235, 60% of each block's transaction fees go into a reserve and miners keep the remaining 40%. Under ZIP 237, each block then reissues a small, predictable portion of that reserve on top of its normal reward. The four-year halving schedule and the 21 million ZEC supply cap stay unchanged.
