Invoice

A Lightning payment request — a string starting with "lnbc..." that encodes amount, description, and destination.

A Lightning invoice is a payment request created by the receiver. It encodes the amount being requested, an optional description, the receiver's node identity, and a one-time secret that the sender uses to settle the payment. Invoices typically start with "lnbc..." and can be encoded as a QR code for easy scanning.

Invoices are typically single-use — once paid, the same invoice can't be paid again. They have an expiry (often an hour) after which they're no longer valid. This is different from on-chain Bitcoin addresses, which are reusable — though reusing addresses is a privacy mistake.

For sending, the BTCBitByBit wallet handles invoices automatically. You scan the QR code or paste the string, the wallet decodes it, shows you the amount and description, and asks you to confirm. The sats arrive at the receiver in roughly a second.

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Lightning Network

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Related terms

Glossary

Lightning Network

A second-layer Bitcoin payment network that enables instant, low-fee transactions.

Glossary

Channel

A two-party Lightning payment connection. Open it once, exchange thousands of payments off-chain, close it when done.

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