Public network reference

Bitcoin BIP110

A public resource for understanding Bitcoin BIP110, the history behind the chain split, and the implications for Bitcoin holders.

Read the Overview Implications for Users

Bitcoin BIP110 at a glance

How Bitcoin BIP110 was created.

On 8 August 2026, the mandatory enforcement of BIP 110 on the Bitcoin BTC mainnet caused a chain split at block height 961,632. The new chain became Bitcoin BIP110.

Bitcoin mainnet Genesis through block 961,631 Bitcoin BTC and Bitcoin BIP110 shared the same UTXO history pre-split.

Split at height 961,632

Bitcoin mainnet continuation branch

Bitcoin BTC

Algorithm: SHA-256d Proof-of-Work
Primary Implementation: Bitcoin Core
Maximum Supply: 21,000,000
Circulating Supply at Split: 20,067,600
Exchange Listed Name: Bitcoin
Exchange Listed Ticker: BTC

BIP 110 enforcement branch

Bitcoin BIP110

Algorithm: BLAKE2b Proof-of-Work
Primary Implementation: Bitcoin Knots
Maximum Supply: 21,000,000
Circulating Supply at Split: 20,067,600
Exchange Listed Name: Bitcoin BIP110
Exchange Listed Ticker: BIP110

Explore the reference

History of Bitcoin BIP110

Read the chain lineage, verify dated events, and inspect the fields required by node operators, miners, wallets, exchanges, and custodians.

From BIP 110 to an independent chain

The original proposal, the enforcement split, and the BLAKE2b continuation.

Read the detailed history → 02

Timeline of key events and milestones

Follow the implementation path from the chain split through BLAKE2b mainnet activation and the production release.

See the timeline → 03

Integration facts and chain identity

Consensus, address, release, replay, mining, and RPC verification data.

Review technical data →

Current state

Current protocol and network status of Bitcoin BIP110.

Verified

The chain split at height 961,632 and the early SHA-256d branch.

Verified

Block 961,639 is the final SHA-256d block on the Bitcoin BIP110 branch.

Active

BLAKE2b proof of work and the 164-byte version-2 header are active from block 961,640.

Released

Bitcoin Knots 29.4.1.knots20260508 is the signed production reference release.

Wallet safety

Safety considerations after the chain split.

Ordinary transactions can remain valid across compatible histories. SIGHASH_UNIFIED is an opt-in, signature-specific replay-protection mechanism implemented in the production Bitcoin Knots reference release.

Do not move inherited coins without understanding replay behavior and verifying the exact software and rules active on both chains.

Review the unified signature-hash implementation

From Bitcoin to Bitcoin BIP110

The documented history of Bitcoin BIP110.

Read the full history