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Replace-by-fee (RBF) Bitcoin

Replace-by-fee (RBF) is a feature that allows users to replace one version of an unconfirmed transaction with a different version of the transaction that pays a higher transaction fee (i.e., bump the transaction fee). This can be done multiple times while the transaction is unconfirmed.

The benefits of RBF are that it allows you to gradually increase the fee until the transaction is accepted into a block. If the need to confirm a transaction becomes more urgent than initially thought, RBF also allows the sender to easily accelerate the transaction and have it added to the next block.

RBF was proposed in BIP125 and the initial implementation was released in Bitcoin Core 0.12.0. 
 

TABLE OF CONTENTS
  • Replace-by-fee in Trezor Suite
  • Bump a transaction fee
  • RBF by output reduction
  • Replace-by-fee with Trezor in Electrum

 

Replace-by-fee in Trezor Suite

RBF is fully implemented in Trezor Suite (as of version 21.2.2) and has on-device support for all Trezor hardware wallets.

 

Bump a transaction fee

Choosing to bump a fee will open a dialog where a new custom fee can be set. This fee must be higher than the previous fee as it adds the difference to the total set in the previous transaction.

Once a new fee is selected in Suite, the transaction must be confirmed once again on your Trezor device, which will display the original transaction that is being replaced and the total fee to be paid.
 



This process can be repeated as many times needed. A total of all fee bumps will be paid.  


RBF by output reduction

When sending the maximum amount of bitcoin stored on a single account, there will be no leftover balance to increase the fee from. RBF by output reduction takes the additional fee from the amount being transferred, instead of the account balance.

Using RBF output reduction can be done in the same way as bumping the fee, as long as RBF was enabled when the transaction was sent.
  • To speed up confirmation times when sending the full balance of an account, click Bump fee on the pending transaction.
  • A new window will open where a new fee can be set.
  • Trezor Suite will show a message that there are no funds left for the fee, and that the amount sent must be reduced.
  • Set a new fee and confirm the new settings. The additional fee will then be reallocated from the transaction output.

 

Replace-by-fee with Trezor in Electrum

It is possible to use Replace-by-fee with Trezor device in Electrum. The original transaction can be replaced only if it was made using Electrum with the "Replace by fee" option on (Tools - Preferences - Replace by fee).