Zero Confirmation
A transaction that has been broadcast but not yet included in a block, so it has zero confirmations.
- Also known as
- 0-conf
A zero-confirmation transaction is visible to the network before it is mined or validated into a block. It can feel instant, but it has not yet received the settlement assurance that confirmations provide.
Zero-confirmation safety depends on transaction value, fee level, network policy, mempool propagation, and whether conflicting transactions can replace it. RBF and double-spend attempts are especially relevant for merchants.
Merchants that accept 0-conf often use wallets or processors that watch for conflicts, require reasonable fees, check propagation, and escalate higher-value payments to one or more confirmations.
Related terms
6 linkedExplore connected entries beyond the alphabetical index.
Transaction
→A signed data message that asks a blockchain to transfer value, execute code, or update state.
Block
→A batch of valid transactions added to a blockchain, linked to the previous block by a cryptographic hash.
Double Spend
→A double spend is an attempt to spend the same coins twice by getting one conflicting transaction accepted over another.
Replace By Fee (RBF)
→A Bitcoin node policy (BIP125) allowing an unconfirmed transaction to be replaced by a new one that pays a higher fee.
Opt-in RBF
→A Bitcoin policy allowing unconfirmed transactions to be replaced by a higher-fee version from the same inputs.
CPFP
→A fee-bumping technique where a new transaction spends an unconfirmed output and pays a high fee to incentivize miners to include both.
All terms and definitions may update as the Cryptionary improves.
