Bitcoin BIP-110 signaling window set to begin near Aug. 9, 2026

The mandatory signaling phase is due at block 961632, with support at about 2.64% as of July 27, highlighting a sharp gap between upgraded and non-upgraded node behavior if adoption does not improve.

BTC

Summary

Bitcoin’s BIP-110 mandatory signaling window is scheduled to start at block 961632, which is expected around Aug. 9, 2026. As of 8:40 EDT on July 27, the chain height stood at 959842, leaving roughly 1,790 blocks before the threshold, while signaling support was near 2.64%. If that level of support holds, nodes running BIP-110 would begin rejecting blocks that do not include version bit 4 signaling, while non-upgraded nodes would keep following the chain with the most cumulative proof-of-work (total mining work securing the network). The setup points to a potential divergence in how different parts of the network validate blocks if more miners or node operators do not adopt the signaling requirement.

Terms & Concepts
  • BIP-110: A Bitcoin Improvement Proposal that introduces a version-signaling requirement.
  • version bit 4 signaling: A block-version flag miners use to indicate support for a proposed Bitcoin change.
  • proof-of-work: A consensus system where miners secure the chain through computational work.