Lightning & L2

Lightning invoices

A one-time payment request — scan it, pay it, done in a second.

In plain words

A Lightning payment starts with the person getting paid. They create an invoice — a long code, usually shown as a QR — that says how much and to whom, plus a built-in secret that becomes your receipt. You scan, approve, and the money arrives in about a second. Invoices are one-time-use and expire, usually within a day. That's on purpose: nothing to reuse, nothing to leak.

Why it matters

  • Paying it proves payment — the secret you learn is the receipt.
  • Exact amounts and expiry prevent overpaying and double-paying.
  • The flow is backwards from cards: the payee asks, you approve, nothing of yours is stored.

Not to be confused with

  • A bitcoin address — addresses receive on-chain and can wait forever; invoices are Lightning-only and expire.

Go deeper

Updated 2026-07-29