Child-Pays-For-Parent (CPFP)
CPFP is a Bitcoin technique where a high-fee follow-up transaction (child) is created that speeds confirmation of a low-fee parent transaction, because miners bundle both.
CPFP is the recipient-side version of fee bumping. If someone sends you a transaction with too low a fee and it stalls, you can create a follow-up transaction spending one of those unconfirmed outputs with a much higher fee. Miners compute the combined fee rate (parent + child) across total weight and include both simultaneously. Advantage over RBF: works even if you aren't the sender, or if the original transaction wasn't RBF-signalled.
Example
An exchange sends you 0.5 BTC with too low a fee. You receive it and immediately create a tx sending that 0.5 BTC to yourself with a high fee. Parent (low) + child (high) are mined together — both confirmed.
Frequently asked questions
CPFP vs RBF for the recipient?
You can't RBF someone else's tx. CPFP works: spend the unconfirmed output with a follow-up at high fee. CPFP is the only option if you didn't send.
Does CPFP always work?
In theory yes, in practice best in mempool systems with 'ancestor fee-rate' mining (Bitcoin Core default). Less effective in some pool implementations.
Related terms
Further reading
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