> For the complete documentation index, see [llms.txt](https://docs.leather.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.leather.io/learn/replace-by-fee-rbf.md).

# What is Replace-By-Fee (RBF)?

Replace-By-Fee (RBF) replaces an unconfirmed Bitcoin transaction with a copy that pays a higher fee. How to use it in Leather.

Replace-By-Fee (RBF) replaces an unconfirmed Bitcoin transaction with a new version that pays a higher fee. Miners pick transactions with higher fee rates first, so the new version usually confirms sooner. Only one version can confirm; the other is dropped.

## How RBF works

When the network is busy, a transaction with a low fee rate can wait in the [mempool](/learn/mempool.md) for a long time. With RBF, the sender signs a replacement that spends the same inputs with a higher fee and broadcasts it. Nodes accept the replacement if it pays more than the original.

* **Opt-in RBF:** the original transaction signals that it can be replaced, through its sequence numbers.
* **Full RBF:** nodes accept a higher-fee replacement whether or not the original signaled it.

Only the sender can replace a transaction. A recipient waiting for a payment can use [CPFP](/learn/accelerate-bitcoin-transactions-cpfp.md) instead.

## Increase a fee in Leather

1. On the Home screen, open the "Activity" tab.
2. On the pending Bitcoin transaction you sent, click "Increase fee".
3. Set the new fee and confirm.

See [Increase Transaction Fee](/transactions/increase-fee.md).

![Increase fee button on a pending BTC send in the Activity tab](https://4209755586-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FaSQhveafXrLjROsW3JZ1%2Fuploads%2F7gxzTf2RAn5lOmHIEmaQ%2Fe-support-replace-by-fee-rbf-01-activity-increase-fee.png?alt=media\&token=e5bb089d-e74c-4c32-b12d-6002f71e3d62)

A replacement is a new transaction with a new TXID. Until one version confirms, a recipient should not treat the payment as final. See [What is Double Spending?](/learn/double-spending.md).