Phoenix Wallet

Phoenix is a self-custodial mobile Bitcoin wallet built by ACINQ that uses the Lightning Network to send and receive payments. It runs a real Lightning node on the phone — only the user holds the keys — while hiding the operational complexity that normally comes with running Lightning: channel management, liquidity, and route-finding all happen behind a wallet interface that looks and feels like any simple payment app. It is open source and available for Android and iOS, and it has become the reference example of how far Lightning's rough edges can be sanded down without surrendering custody.

Automated channel management

Phoenix removes the manual channel-opening ritual that trips up newcomers. Each user gets a single dynamic channel that grows and shrinks automatically using splicing — the ability to add or remove funds from a live channel without closing it — so balance management happens invisibly. ACINQ operates the Lightning Service Provider (LSP) the wallet connects to for channel creation and inbound liquidity, charging transparent fees for those services while never taking custody of funds. That fee structure is the honest price of convenience: when Phoenix needs to open or splice a channel to receive a payment, the user pays for the on-chain footprint and the liquidity provided, where a custodial wallet would hide the cost inside counterparty risk instead.

Trampoline routing

A phone cannot realistically hold and constantly sync the full Lightning network graph, so Phoenix uses trampoline routing: instead of computing full payment routes itself, it delegates route-finding to a well-connected node, handing over the payment with instructions to deliver it onward to the destination. This saves bandwidth and battery, and it is why payments still succeed after the app has been asleep for a week. The trade-off is a privacy consideration — the trampoline node learns more about a payment than a fully self-routed node would — though onion-wrapped multi-hop trampoline routes mitigate how much any single node sees.

Where it sits in a sovereign stack

Fees, backups, and expectations

Phoenix's model deserves clear-eyed accounting. Receiving works immediately because the LSP stands ready to provide a channel, but that service is priced: when an incoming payment requires new inbound capacity, a fee covering the on-chain operation and the liquidity applies, so the first sats received cost more than the ten-thousandth. Sending pays ordinary Lightning routing fees plus the trampoline service. Recovery is two-layered in a way users should understand before funding the wallet: the standard seed phrase restores on-chain funds unconditionally, while restoring Lightning balance additionally relies on channel state coordinated with ACINQ's infrastructure — self-custodial throughout, but with an operational dependency a fully self-hosted node does not have. None of this is criticism; it is the wallet being honest about where convenience comes from. The practical guidance is the same one D-Central gives for any hot wallet: keep spending amounts, not savings, and let cold storage carry the weight.

Phoenix occupies a deliberate middle position: full self-custody with keys derived from a standard seed phrase, but with operational trust delegated to an LSP for liquidity and routing. That is a different point on the spectrum from running your own Lightning node behind BTCPay Server — more sovereignty than a custodial app, less infrastructure burden than a node in the closet — and for day-to-day spending money it is a defensible one. Many node runners use exactly this split: the homelab node holds channel capacity for receiving and merchant work, while a mobile wallet like Phoenix carries walking-around sats. It is one of several self-custodial Lightning wallets, each with different trade-offs between convenience and privacy; we describe it neutrally. ACINQ also maintains the server side of this stack — see our entries on Eclair and the Lightning Network itself.