Lightning Channel Splicing Enters the BOLT Specification
The Lightning Network's channel-splicing specification was merged into the BOLTs after an extended multi-implementation development process. Splicing allows channel capacity to be changed by replacing the funding transaction while preserving the channel's identity and minimizing payment downtime.
On March 23, 2026, pull request #1160 was merged into the Lightning Network's BOLT specification, formally incorporating channel splicing as feature 62/63. The merge followed a long review process and implementation work across major Lightning software projects.
Splicing changes the capacity of an existing Lightning channel by spending its current funding transaction into a replacement funding transaction. That allows participants to add or remove on-chain funds without closing the old channel and creating an entirely new one. The specification was designed so normal channel operation could resume while the splice transaction awaited confirmation, and the spliced channel could continue to be advertised for routing without a prolonged interruption.
The merge mattered because splicing had already moved beyond a speculative proposal: implementations such as Eclair and Core Lightning had working experience, with LDK also close to completion during the specification process. Standardizing the protocol in the BOLTs turned a multi-year engineering effort into a shared Lightning-network capability with consequences for channel liquidity management and user experience.