What Is BIP-110? Bitcoin's Data-Limit Proposal and the Fork Debate

BIP-110 is a proposed Bitcoin soft fork that limits how much arbitrary data a transaction can carry. Supporters frame it as a defense of Bitcoin's role as sound money. Critics frame it as censorship with real chain split risk. The proposal enters its decisive window in August 2026 and neither camp is backing down. This guide covers the rules and the timeline plus what the fight means for miners.

Key Takeaways

• BIP-110 (Reduced Data Temporary Softfork) is a proposed one-year Bitcoin soft fork that restricts arbitrary data in transactions.
• Seven rules cap most new outputs at 34 bytes, OP_RETURN at 83 bytes, and data pushes at 256 bytes.
• Miner signaling sits under 1% as of July 2026, but a mandatory signaling window near block 961,632 forces the issue in early August.
• Activation is projected for block 965,664 near September 1, 2026, and the rules expire on their own about a year later.
• Miners need no hardware changes, but pool policy decides whose blocks enforcing nodes accept during the window.

What Is BIP-110?

BIP-110 is a proposed temporary Bitcoin soft fork that restricts arbitrary non-financial data in transactions for about one year. The full specification lives in the Bitcoin BIPs repository. Here is the proposal at a glance:

• Full name: Reduced Data Temporary Softfork (RDTS), which first circulated as BIP-444
• Purpose: restrict non-financial data embedded in Bitcoin transactions
• Targets: Ordinals inscriptions, BRC-20 tokens, Runes, and oversized OP_RETURN payloads
• Mechanism: seven consensus rules that cap output sizes and data fields
• Duration: the rules expire on their own about one year after activation
• Status: live and contested, with a mandatory signaling window in early August 2026

The proposal is authored under the pseudonym Dathon Ohm with developer Luke Dashjr credited for the original draft and advice. Authorship remains disputed. Greg Maxwell has alleged Ocean Mining wrote it and Dathon Ohm denies the claim.

What Is a Bitcoin Improvement Proposal?

A Bitcoin Improvement Proposal (BIP) is a formal design document that proposes a change to Bitcoin's protocol or its processes. BIPs receive sequential numbers, which is why this one is number 110.

BIPs fall into three broad types:

• Standards Track: changes to the network protocol or consensus rules
• Informational: guidelines or design discussion
• Process: changes to how decisions get made

A BIP number signals process compliance rather than endorsement. BIP editor Mark "Murch" Erhardt assigned BIP-110 its number while describing it as "a misguided and unusually careless softfork proposal." He published it anyway because it met the repository's criteria. No BIP activates without broad support across miners and the wider economy.

Why Was BIP-110 Proposed?

BIP-110 exists because a wave of data embedding that began in 2022 convinced some Bitcoiners that policy filters were no longer enough.

The Rise of Ordinals and Inscriptions

The "inscription" method appeared in 2022 and stores arbitrary data inside transaction witness fields. Ordinals popularized the technique in early 2023 and brought images and NFT-style assets onto the Bitcoin blockchain. Supporters of BIP-110 call this traffic spam. Users of these protocols call it valid paid block space.

Node Burden and the Fee Market

Proponents argue the economics are lopsided: a miner collects the fee once while every node stores the data forever. Critics respond that the block size limit already caps node costs and that the fee market prices out spam on its own.

From Policy Dispute to Consensus Proposal

The fight escalated after Bitcoin Core v30 removed the long-standing OP_RETURN relay limit in 2025. BIP-110 answers by moving the limits into consensus where no single software release can undo them.

How Does BIP-110 Change Bitcoin's Data Limits?

BIP-110 adds seven consensus rules that cap the size of data fields in new transactions. The common "83-byte" shorthand applies only to OP_RETURN outputs.

Grandfathering is permanent. UTXOs created before activation stay exempt for the entire deployment and there is no deadline to move funds. Existing Ordinals and inscriptions remain on the blockchain untouched.

The soft fork also ends on its own. The rules expire 52,416 blocks after activation, which works out to about one year. Expiry requires no vote and no follow-up change.

How Does BIP-110 Activate?

BIP-110 activates through miner signaling or through a mandatory flag day, and the flag day arrives in August 2026 either way.

Miners signal readiness by setting version bit 4 in the blocks they produce. Early lock-in requires 55% of blocks in a single 2,016-block difficulty period. That is 1,109 signaling blocks or about 110 per day across two weeks. Individual miners signal through whichever mining pool builds their block templates.

Node operators do not signal. They enforce. Running BIP-110 software such as Bitcoin Knots means rejecting blocks that break the rules once they apply. Bitcoin Core has not endorsed the proposal and an implementation submitted to Core has not been merged.

The deployment is a user activated soft fork (UASF). From block 961,632 through block 963,647 enforcing nodes reject any block that does not signal bit 4. Lock-in happens no later than block 963,648. Activation follows at block 965,664 with a projected date near September 1, 2026. The mandatory window is why the rules take effect on enforcing nodes regardless of miner support.

Where Things Stand as of July 2026

Miner support for BIP-110 remains under 1% of blocks while the node debate stays heated.

As of July 2026: signaling sits between 0.4% and 0.8% of recent blocks, which equals about 5 EH/s on a network near 940 EH/s. Mandatory signaling begins near block 961,632 with a projected start around August 7, 2026. Activation is set for block 965,664 near September 1, 2026. Track live numbers on the BIP-110 monitor.

Barefoot Mining produced the first signaling block through the Ocean pool on March 1, 2026. Ocean still accounts for the majority of signals and smaller operations with names like BIP110 and Roughnecks110 supply most of the rest.

No major pool has committed to signaling. Foundry USA controls about a third of network hashrate and Antpool about 14% and neither has moved. F2Pool has refused outright. One large pool announcement would change the picture within days, so treat every figure as a snapshot.

Node adoption is murkier. Bitcoin Knots runs on somewhere between 8% and 23% of reachable nodes depending on the metric. Critics such as Jameson Lopp argue that cheap Tor nodes make raw counts easy to inflate. Supporters point to a steady adoption curve since 2025.

One early criticism has been resolved. A Bitcoin Core developer found a consensus flaw in the reference client in February 2026. The maintainers patched it in client v0.3 and an independent audit later called the implementation clean.

The August Window and What to Watch

The mandatory signaling window near block 961,632 is the moment BIP-110 stops being theoretical.

Bitcoin Core developer Jon Atack advises users to pause transfers around that block because short reorgs are possible. Luke Dashjr counters that upgraded nodes face no reorg risk once BIP-110 locks in.

BIP-110 includes no replay protection because it is not designed to split the chain. If a split happens anyway a transaction could be valid on both chains at once.

Coverage suggests general risk management rather than panic:

• Extra confirmations: if a transfer cannot wait, consider waiting for six to ten confirmations instead of the usual one to three
• Exchange policy: exchanges and custodians may raise deposit confirmation counts and may or may not recognize a split chain
• Self custody: some holders move coins off exchanges before the window and defer large transfers until confirmations stabilize

A chain split remains a possibility rather than an expected outcome given how little miner support exists.

News coverage keeps bundling BIP-110 with a second August event. Paul Sztorc's eCash hard fork targets block 964,000 around August 21, 2026 and would create a separate chain with a 1:1 airdrop. The two are unrelated and the FAQ below covers the difference.

The Bitcoin Fork Debate Around BIP-110

BIP-110 is written as a soft fork, yet its activation method is the reason critics treat it as a fork threat.

Soft Fork vs Hard Fork Explained

A soft fork tightens the rules and old nodes still accept new blocks. A hard fork changes rules in a way old nodes reject, which can create a lasting chain split. BIP-110 qualifies as a soft fork because it only makes rules stricter.

Why Critics Dispute the Label

Critics point to three features. Mandatory signaling means enforcing nodes reject blocks from miners who never agreed to the change. Wallets that use now-prohibited features face forward compatibility breakage even though nodes do not. And the 55% lock-in threshold replaces the traditional 95% standard for soft forks. Jameson Lopp's critical walkthrough argues these choices raise chain split risk well past prior soft forks.

Lessons From Previous Bitcoin Forks

SegWit activated in 2017 after the block size wars split the community for years. The UASF threat of that era (BIP 148) never triggered because SegWit locked in through miner signaling first. Critics cite that history to argue UASF safety is unproven. Supporters draw the opposite lesson and say the threat alone moved miners.

Arguments For and Against BIP-110

Both camps make claims worth weighing.

Why Supporters Back BIP-110

• Anti-spam protection: limiting data keeps block space available for payments and holds fees down for monetary use
• Node accessibility: slower data growth keeps running a full node cheap
• Sound money focus: rejecting data storage as a supported use case keeps Bitcoin focused on its role as money
• Temporary by design: the rules lapse on their own after about one year
• Split skepticism: supporters argue miners will not sacrifice block rewards over spam fees once the choice is real

Why Critics Oppose BIP-110

• Censorship precedent: consensus rules that filter transaction types set a precedent critics consider dangerous
• Innovation suppression: control block limits constrain BitVM and covenant research along with Miniscript edge cases
• Governance concern: some describe the campaign as a "hostile takeover" attempt by a small group
• Aggressive activation: a 55% threshold and mandatory signaling raise chain split risk
• Fund freezing edge cases: the specification itself concedes rare pre-signed Taproot transactions could freeze funds
• No replay protection: a split would leave transactions valid on both chains

Prominent names anchor the opposition. Adam Back argues the proposal breaks multiple things without stopping the embedding it targets and calls each flaw "fatal." Michael Saylor describes it as Bitcoin's "biggest self-inflicted risk." Peter Todd embedded the full BIP text inside a compliant transaction to show determined data storage survives the rules. The specification concedes the rules raise the cost of data storage rather than eliminate it.

What Does BIP-110 Mean for Bitcoin Miners?

BIP-110 changes which transactions are valid, and that touches fee revenue and pool policy more than hardware.

Fee Revenue and Transaction Selection

Miners select the highest paying transactions waiting in the mempool. Ordinals and Runes activity pays real fees and has become a meaningful slice of miner revenue. That link helps explain thin miner interest in restricting the traffic. Fee swings feed straight into hashprice, so any rule that removes fee-paying demand matters to every operator.

Pool Positioning

Pools set the version bits in the blocks they build. Here is what can go wrong: a pool with no declared policy mines non-signaling blocks during the mandatory window and enforcing nodes orphan those blocks on their side of the network. The mitigation is simple. Ask your pool for its version bit policy before August and switch pools if the answer worries you.

Hardware Is Chain Agnostic

An ASIC computes SHA-256 for whichever chain its pool points it at. No firmware update or hardware change follows from BIP-110. Pool selection is where a miner's exposure to this debate lives.

How Should Miners Prepare for Bitcoin Protocol Changes?

Protocol fights are a permanent feature of Bitcoin, so preparation beats prediction.

• Stay informed: follow the signaling monitor and major developer communications through August
• Know your pool: confirm your pool's version bit policy and its plan for the mandatory window
• Focus on fundamentals: uptime and efficiency drive mining profitability no matter which proposals activate
• Let operations absorb the noise: machines that keep hashing through protocol debates need no patch and no vote

Hosted mining customers need no direct action on BIP-110. Machines hash for whichever pool the owner selects and payouts continue. If you want to see how hands-off mining works before the August window, Simple Mining's free 7-day trial runs 100 TH/s with your own pool and wallet settings.

FAQs

What happens to existing Ordinals if BIP-110 activates?

Existing Ordinals and inscriptions remain on the blockchain and stay spendable. BIP-110 grandfathers every UTXO created before activation for the entire deployment. The rules apply only to new outputs created after activation.

Is BIP-110 the same as increasing Bitcoin's block size?

No. BIP-110 restricts certain data types and leaves the block size unchanged. It is a data-limit proposal rather than a scaling proposal.

Can BIP-110 be reversed after activation?

BIP-110 does not need reversal because it expires on its own. The rules lapse 52,416 blocks after activation, which works out to about one year. Extending the limits would require a new proposal and fresh consensus.

Is BIP-110 the same as the eCash fork?

No. BIP-110 is a soft fork that tightens data rules on the existing Bitcoin chain, while eCash is a separate hard fork planned by Paul Sztorc near block 964,000 with a 1:1 airdrop. Their August 2026 timing overlaps but the two events are unrelated.

Which mining pools support or oppose BIP-110?

As of July 2026 no major pool signals for BIP-110 and F2Pool has refused outright. Ocean produces the majority of signaling blocks. Check your pool's public statements before the August window.

Will there be more proposals like BIP-110?

More proposals are likely. The BIP-110 specification invites a longer-term successor once it expires. Some supporters favor a stricter follow-on idea known as The Cat, and Bitcoin's open process lets anyone submit the next one.

Blocks Settle the Debate

Bitcoin settles its arguments in blocks rather than in posts. BIP-110 gets its answer between block 961,632 and block 965,664 no matter how loud either camp gets. Miners who know their pool's stance lose nothing on either outcome. Whichever way the window breaks, steady hashrate is what carries you through it. Simple Mining handles hosted Bitcoin mining so your machines keep running through the noise, and you can buy Bitcoin miners when you want to add hashrate.

By Josh Heine, Content Strategist at Simple Mining
Published: July 9, 2026