# Lightning channels: balances, commitments and closing A Lightning payment channel lets participants update their claims on bitcoin committed to a funding output without publishing every payment as a separate Bitcoin transaction. Commitment transactions and channel rules provide on-chain enforcement paths. Opening, closing, liquidity and monitoring requirements still matter. Evidence: [BOLT 2: Peer Protocol for Channel Management](https://raw.githubusercontent.com/lightning/bolts/1aadb719b4007c4cea0ba6e36b08c4fb53788dee/02-peer-protocol.md) Canonical: https://degreesofsatoshi.com/encyclopedia/lightning-payment-channels/ Published: 2026-10-02 Substantively modified: 2026-10-02 Independently verified by an automated reviewer: 2026-10-02T18:15:23.891Z Data current through: 2026-10-02 AI-assisted research and drafting with a separate automated source-verification pass; no external expert or named human review is implied. ## Key facts - **Funding:** Channel establishment commits funds through a Bitcoin funding transaction. ([BOLT 2: Peer Protocol for Channel Management](https://raw.githubusercontent.com/lightning/bolts/1aadb719b4007c4cea0ba6e36b08c4fb53788dee/02-peer-protocol.md)) - **Updates:** Participants exchange messages and signatures that advance the channel state. ([BOLT 2: Peer Protocol for Channel Management](https://raw.githubusercontent.com/lightning/bolts/1aadb719b4007c4cea0ba6e36b08c4fb53788dee/02-peer-protocol.md)) - **Exit:** Cooperative closing and unilateral commitment-based closing have different requirements. ([BOLT 2: Peer Protocol for Channel Management](https://raw.githubusercontent.com/lightning/bolts/1aadb719b4007c4cea0ba6e36b08c4fb53788dee/02-peer-protocol.md)) ## Move claims within an existing allocation For a simplified example, a channel has 100,000 satoshis of capacity, with 70,000 on Alice’s side and 30,000 on Bob’s. A 10,000-satoshi payment from Alice to Bob shifts the allocation toward 60,000 and 40,000, before accounting for actual reserves, pending HTLCs and fees. No new bitcoin is created by this update. The parties change which claims can be enforced against the channel’s funding. Evidence: [BOLT 2: Peer Protocol for Channel Management](https://raw.githubusercontent.com/lightning/bolts/1aadb719b4007c4cea0ba6e36b08c4fb53788dee/02-peer-protocol.md) ## A network payment can cross multiple channels Conditional payments allow a route to link transfers through intermediate nodes. Each hop needs usable capacity in the right direction and acceptable fee and timing conditions. A large total channel capacity does not guarantee that a particular payment route is available. Capacity placement, pending transfers and individual channel limits affect routing. Evidence: [BOLT 2: Peer Protocol for Channel Management](https://raw.githubusercontent.com/lightning/bolts/1aadb719b4007c4cea0ba6e36b08c4fb53788dee/02-peer-protocol.md); [BOLT 7: P2P Node and Channel Discovery](https://raw.githubusercontent.com/lightning/bolts/1aadb719b4007c4cea0ba6e36b08c4fb53788dee/07-routing-gossip.md) ## On-chain enforcement has costs and timing Participants may agree on a cooperative close, or a party may publish a commitment transaction under the channel’s rules. Unilateral paths can involve delay and additional transactions. Keeping correct channel state and responding within relevant timing conditions are part of the security model. A channel is not simply a bank balance that remains safe under every backup or offline behavior. Evidence: [BOLT 2: Peer Protocol for Channel Management](https://raw.githubusercontent.com/lightning/bolts/1aadb719b4007c4cea0ba6e36b08c4fb53788dee/02-peer-protocol.md) ## Questions ### Does each Lightning payment create a Bitcoin block transaction? No. Ordinary channel updates occur off-chain. Funding and closing or dispute-enforcement transactions connect the channel’s state to the Bitcoin chain. Evidence: [BOLT 2: Peer Protocol for Channel Management](https://raw.githubusercontent.com/lightning/bolts/1aadb719b4007c4cea0ba6e36b08c4fb53788dee/02-peer-protocol.md) ## Claims and scope ### lightning-payment-channels-quick-answer A Lightning payment channel lets participants update their claims on bitcoin committed to a funding output without publishing every payment as a separate Bitcoin transaction. Commitment transactions and channel rules provide on-chain enforcement paths. Opening, closing, liquidity and monitoring requirements still matter. Scope: {"collection":"bitcoin","dataAsOf":"2026-10-02","blockHeight":null} ### lightning-payment-channels-fact-funding Funding: Channel establishment commits funds through a Bitcoin funding transaction. Scope: {"collection":"bitcoin","dataAsOf":"2026-10-02","blockHeight":null} ### lightning-payment-channels-fact-updates Updates: Participants exchange messages and signatures that advance the channel state. Scope: {"collection":"bitcoin","dataAsOf":"2026-10-02","blockHeight":null} ### lightning-payment-channels-fact-exit Exit: Cooperative closing and unilateral commitment-based closing have different requirements. Scope: {"collection":"bitcoin","dataAsOf":"2026-10-02","blockHeight":null} ## Sources - [BOLT 2: Peer Protocol for Channel Management](https://raw.githubusercontent.com/lightning/bolts/1aadb719b4007c4cea0ba6e36b08c4fb53788dee/02-peer-protocol.md) — Lightning specification contributors. Channel funding, commitment updates, forwarding and channel closing. Locator: Channel Establishment; Forwarding HTLCs; Channel Close. Retrieved: 2026-10-02T17:22:20.750Z. - [BOLT 7: P2P Node and Channel Discovery](https://raw.githubusercontent.com/lightning/bolts/1aadb719b4007c4cea0ba6e36b08c4fb53788dee/07-routing-gossip.md) — Lightning specification contributors. Direction-specific advertised routing fees and channel update parameters. Locator: The channel_update Message; HTLC Fees; Example; fee_base_msat; fee_proportional_millionths. Retrieved: 2026-10-02T17:22:20.753Z. ## Revision history - 2026-10-02: Initial Bitcoin encyclopedia entry at this permanent URL. - 2026-10-02: Added reusable claims, explicit source locators, and matching Markdown and JSON. This publishing change does not itself establish factual verification. ## Cite this entry Degrees of Satoshi editorial project. “Lightning channels: balances, commitments and closing.” Published 2026-10-02; updated 2026-10-02. https://degreesofsatoshi.com/encyclopedia/lightning-payment-channels/