Opt-in RBF
A Bitcoin policy allowing unconfirmed transactions to be replaced by a higher-fee version from the same inputs.
- Also known as
- replace-by-fee (opt-in)RBF
Opt-in Replace-By-Fee (RBF) is a Bitcoin transaction relay policy that lets a sender replace an unconfirmed transaction with a new one paying a higher fee, provided the original signaled RBF or the network treats it as replaceable.
This improves fee-bumping and stuck tx recovery but reduces the reliability of zero-confirmation acceptance on networks that use it.
RBF is useful for increasing fee rates during congestion, and wallets may expose it as "bump fee" or "speed up." Its effect depends on relay policy, wallet support, and whether the transaction is still unconfirmed.
RBF policy differs across Bitcoin-family networks. Bitcoin Cash does not use Bitcoin's opt-in RBF model for ordinary payments, which is one reason BCH merchants often discuss zero-confirmation risk differently from BTC merchants.
Related terms
5 linkedExplore connected entries beyond the alphabetical index.
Mempool
→A temporary storage space in a node for pending transactions that have not yet been included in a confirmed block.
Fee Rate
→A fee rate is the transaction fee per unit of size, such as satoshis per vbyte, used to prioritize block inclusion.
Zero Confirmation
→A transaction that has been broadcast but not yet included in a block, so it has zero confirmations.
Double Spend
→A double spend is an attempt to spend the same coins twice by getting one conflicting transaction accepted over another.
Bitcoin (BTC)
→The first widely adopted cryptocurrency, using proof of work and a fixed 21 million coin supply.
All terms and definitions may update as the Cryptionary improves.
