BIP-110
BIP-110 - Temporary Data Reduction
| Year | 2025 (proposed) |
| Type | UASF (temporary soft fork) |
| BIP | BIP-110 |
| Status | Proposed |
What it does
BIP-110 introduces relay and consensus rules that filter transactions primarily used for data embedding (such as Ordinals inscriptions) rather than financial transfers. It is designed as a temporary measure that auto-expires after approximately one year.
Why it was proposed
Since the emergence of Ordinals (February 2023) and Runes (April 2024), non-financial data has grown to occupy a significant portion of Bitcoin block space:
- 41% of block space is non-financial data (last 90 days, Renaud Cuny, Bitcoin Block Space Weekly)
- 136 million non-financial transactions over 3.5 years
- 76 GB of non-financial data stored on every full node, permanently
Bitcoin Core v30 (2025) removed the 80-byte OP_RETURN limit, increasing it to approximately 100 KB (a 1,250x increase). This change was opposed 4:1 in public GitHub discussion (423 against, 105 for). BIP-110 is a community response to this change.
Timeline
| Milestone | Block height | Estimated date |
|---|---|---|
| Signaling begins | Timestamp 1764547200 | ~December 1, 2025 |
| Early lock-in | Any retarget period where 55% signal (1,109/2,016 blocks) | |
| Mandatory signaling | 961,632 - 963,647 | ~August 7, 2026 |
| Lock-in (latest) | 963,648 | ~August 21, 2026 |
| Activation (latest) | 965,664 | ~September 4, 2026 |
| Auto-expiry | 1,018,080 (activation + 52,416) | ~September 3, 2027 |
Date estimates based on current block height 952,709 (June 7, 2026) and 10-minute average block time. Actual dates will vary.
Miners signal readiness by setting version bit 4 in the blocks they mine. If 55% is reached in any retarget period, lock-in happens early. If not reached voluntarily, mandatory signaling begins at block 961,632. After expiry, the rules automatically deactivate unless renewed.
What is mandatory signaling?
During normal signaling, miners choose whether to set the version bit. If the 55% threshold is not reached voluntarily, BIP-110 enters a mandatory signaling period (blocks 961,632 - 963,647). During this window, nodes running BIP-110 will reject blocks that do not set the signal bit - effectively requiring miners to either signal support or have their blocks orphaned by BIP-110 nodes.
This is the same mechanism used by BIP-148 (the UASF that forced SegWit activation in 2017). It shifts the decision from “do miners want this?” to “are miners willing to lose blocks over opposing it?” Since BIP-110 is a UASF, mandatory signaling is the backstop that ensures activation happens regardless of voluntary miner cooperation.
Key features
- Temporary: Auto-expires after approximately one year. If not renewed, the chain returns to previous rules.
- Activation threshold: 55% miner signaling (lower than traditional 90-95%, but the rules are temporary)
- Grandfather clause: All pre-activation UTXOs are exempt. No existing funds are affected.
- Filter effectiveness: Simulations show 99% reduction in non-financial transactions when rules are active (Chris Guida data), with 99.95% accuracy and zero legitimate smart contracts blocked (Renaud Cuny, Bitcoin Block Space Weekly Issue #8)
Common questions
Does it confiscate funds?
No. The grandfather clause exempts all pre-activation UTXOs. Pre-signed transactions spending pre-activation outputs are unaffected.
Can spammers bypass it?
Some bypass is possible, but “easily bypassed” does not mean “ineffective.” Empirical data shows 99% reduction when filters are active. Perfect enforcement has never been the standard for any relay policy in Bitcoin.
Does it set a precedent for worse changes?
Every fork happens in a completely different environment - different technology, reward epoch, developers, hardware, economics. A temporary data filter and a permanent monetary policy change operate under fundamentally different incentive structures. Vigilance about precedent is healthy, but the comparison does not hold in practice.
Data sources
| Metric | Value | Source |
|---|---|---|
| Non-financial block space | 41% (last 90 days) | Renaud Cuny, Block Space Weekly |
| Non-financial transactions | 136M over 3.5 years | Renaud Cuny |
| Data stored on every node | 76 GB | Renaud Cuny |
| Filter effectiveness | 99% reduction | Chris Guida |
| Simulation accuracy | 99.95% correct catches | Renaud Cuny, Issue #8 |
| Legitimate contracts blocked | 0 | Renaud Cuny, Issue #8 |
| OP_RETURN limit increase | 1,250x (80b to 100KB) | Bitcoin Core v30 |
| Community opposition to v30 | 4:1 (423 vs 105) | GitHub PR |
| Inscription fee premium | 0.08% of block reward | Ocean vs SpiderPool comparison |
Links
- bip110.org - Community hub with installation guides, technical specs, and FAQ
- BIP-110 full text
- Bitcoin Block Space Weekly (Renaud Cuny)
- BIP-110 Game Theory & Code Audit
- OP_RETURN Limit Removal Analysis
- Shodan Bitcoin nodes - Internet-wide scan of clearnet nodes (versions, geoIP, hosting)