What Is BIP-110? Inside Bitcoin's Contested Soft Fork Fight
BIP-110 would let miners reject blocks that don't restrict Ordinals, BRC-20, and Runes transactions — but signaling sits near 2.6%, far below the 55% needed. How soft fork activation actually works, and what a chain split would mean.
BY DEREK CHU6 MIN READ
What BIP-110 actually proposes
BIP-110 is a contested proposal to cap OP_RETURN payloads and restrict non-monetary data from Bitcoin transactions — the mechanism behind Ordinals, BRC-20 tokens, and Runes. Like any bitcoin soft fork, it needs miners to signal support during a defined window before it can activate: this one requires 55% of blocks to signal within the window. The most recent signaling window opened with almost no support — pool signaling has run near 2.6%, and an earlier attempt in July mined only two blocks in favor before stalling entirely.
How soft fork activation works — and what a split would mean
Bitcoin's soft forks activate by rough miner consensus, not a formal vote: nodes running the new rules reject any block that doesn't signal compliance once the activation height is reached. If enough of the network doesn't upgrade, that creates the technical possibility of a chain split — a period where two versions of the ledger both exist. Developer Kevin Loaec has warned that if a split ever did occur, holders would have equal balances on both resulting chains, but trying to sell coins from either chain without first separating the balances risks a replay attack, where the same transaction gets rebroadcast on the chain you didn't intend to spend from.
WHY IT MATTERS
Bitcoin's upgrade process is deliberately hard to move without broad agreement — that's a feature, not a bug. BIP-110's near-total lack of miner support makes activation very unlikely, but the fight over it exposes a real, ongoing disagreement about what kind of data belongs on the base chain. A disputed rule change is different from a 51% attack, in which majority hashpower attempts to reorganize recent transactions.
What to watch next
1.Whether signaling improves at all before the current window closes, or stalls the way the July attempt did.
2.Whether any major mining pool issues a public statement for or against the proposal.
3.Whether a future, better-supported proposal revives the same OP_RETURN debate in a different form.
Frequently asked questions
What is a soft fork?
A protocol change that tightens the rules for what counts as a valid block, without breaking compatibility for nodes that haven't upgraded. Old nodes still accept new blocks; they just can't produce non-compliant ones once activation is reached.
What's the difference between a soft fork and a hard fork?
A soft fork narrows the rules in a backward-compatible way. A hard fork loosens or changes them in a way old nodes reject outright, forcing every participant to upgrade or split onto a separate chain.
What happens to my bitcoin if BIP-110 fails to activate?
Nothing. If a soft fork attempt doesn't reach its signaling threshold, it simply expires and the network keeps running under the existing rules — your coins and balances are unaffected.
SOURCES & DATA
Education, not financial advice. See our editorial process and corrections policy.
Derek Chu
Bitcoin Almanack's editorial byline for on-chain data, holder behavior, exchange flows, network activity, and technical market structure.
Sources, standards & corrections
Sources are linked inline. Read our editorial information, AI disclosure and corrections policy, or report an error.
Sources are linked inline. Read our editorial information, AI disclosure and corrections policy, or report an error.