# replace-by-fee

URL: https://blockspace.wiki/glossary/replace-by-fee/

A node policy that lets an unconfirmed transaction in a [mempool](https://blockspace.wiki/glossary/mempool/) be replaced by a different transaction that spends at least one of the same inputs and pays a higher fee. The most widely used form is BIP 125 opt-in RBF, where a transaction signals that it may be replaced; [full-RBF](https://blockspace.wiki/glossary/full-rbf/) allows any transaction to be replaced, signalled or not.

Sources:

- Bitcoin Optech: replace-by-fee (RBF) · https://bitcoinops.org/en/topics/replace-by-fee/
- BIP 125: opt-in full replace-by-fee signaling · https://github.com/bitcoin/bips/blob/master/bip-0125.mediawiki

Updated: 2026-10-21