# Replace-by-fee (RBF)

Replace-by-fee lets you resend an unconfirmed Bitcoin transaction with a higher fee so it confirms faster. Learn the rules and how wallets do it.

Canonical page: https://mybitcoinexplorer.com/learn/replace-by-fee-rbf
Topic: Transactions
Published: 2026-10-29
Updated: 2026-10-30


## Bumping a stuck payment
If your transaction is stuck because the fee was too low, you can broadcast a **replacement**: a new transaction that spends at least one of the same inputs and pays a higher fee. Nodes swap the old one for the new one in their [mempool](https://mybitcoinexplorer.com/learn/what-is-the-mempool).

> Diagram: The higher-fee version replaces the original, which can then never confirm — 

## The main rules
A replacement must:
- spend at least one of the same inputs (so the two conflict),
- pay a **higher total fee** than the original,
- pay extra enough to cover its own size at the node's minimum relay rate.

## Signalling
Originally, a transaction had to opt in to RBF by setting a [sequence](https://mybitcoinexplorer.com/learn/locktime-and-sequence) number below `0xfffffffe` (BIP 125). Since Bitcoin Core 28.0, nodes by default accept replacements whether or not the original signalled. Many wallets show a "bump fee" button for this.

## What RBF means for receivers
An unconfirmed payment can be replaced, even with one that pays someone else. That's why merchants should wait for at least one [confirmation](https://mybitcoinexplorer.com/learn/bitcoin-confirmations) for anything valuable.


## How to bump a fee in practice
1. Find the unconfirmed payment in your wallet.
1. Choose "bump fee", "speed up" or "increase fee".
1. Pick a new fee rate above the current next-block estimate.
1. Confirm. The wallet broadcasts the replacement; the old version disappears from mempools.

## How much higher?
The replacement must pay more in total and enough extra to cover its own size at the minimum relay rate. Wallets work this out for you.


## Key takeaways

- RBF replaces an unconfirmed transaction with a higher-fee version.
- The replacement must conflict with the original and pay more.
- Unconfirmed payments are never final.

## Common questions

### Can I cancel a Bitcoin transaction with RBF?

Sometimes: replace it with one that sends the coins back to yourself at a higher fee. It only works if the original hasn't confirmed.

### Is RBF the only way to speed up a transaction?

No, the receiver (or you, using change) can also use child-pays-for-parent.

### Does RBF cost extra?

You pay the new, higher fee instead of the old one, not both.

### Can I use RBF after the transaction confirms?

No. Once confirmed, a transaction can't be replaced.

## Related lessons

- [Child pays for parent (CPFP)](https://mybitcoinexplorer.com/learn/child-pays-for-parent-cpfp)
- [How Bitcoin transaction fees work](https://mybitcoinexplorer.com/learn/bitcoin-transaction-fees)
- [Locktime and sequence](https://mybitcoinexplorer.com/learn/locktime-and-sequence)
- [What is the Bitcoin mempool?](https://mybitcoinexplorer.com/learn/what-is-the-mempool)