RBF

Replace-By-Fee — a way to bump up the fee on an unconfirmed transaction so it confirms faster.

Replace-By-Fee (RBF) is a feature that lets you replace an unconfirmed Bitcoin transaction with a new version that pays a higher fee. It's useful when fees rise after you broadcast a transaction with a low fee — rather than waiting hours or days for confirmation, you bump the fee and the new transaction takes priority.

For RBF to work, the original transaction must have been broadcast with the RBF flag set. Most modern wallets enable this by default. When you "speed up" a stuck transaction in your wallet, RBF is what's happening under the hood.

The receiver should never accept an unconfirmed RBF transaction as final — it can be replaced. Wait at least one confirmation before treating it as settled. This is why exchanges and merchants have minimum-confirmation rules.

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Mining & nodes

How Bitcoin actually works. Miners, nodes, blocks, and what running your own changes.

Related terms

Glossary

Mempool

The waiting room of unconfirmed transactions — where every Bitcoin transaction sits before being included in a block.

Glossary

On-chain

A Bitcoin transaction settled directly on the main blockchain. Slower and more expensive than Lightning but the ultimate settlement layer.

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