Skip to article
Degrees of SatoshiFollow the connections.
SearchTrace an address
Degrees of Satoshi/ Encyclopedia

Encyclopedia How the network works · Entry 76

Replace-by-fee: replacing a pending Bitcoin payment

AI-assisted research · separate automated verificationCorrections

Theme
How the network works
Sources
5 cited records
Reading time
About 3 minutes
Automated verification
Substantive update
In this article

At a glance

Key facts

Key facts for Replace-by-fee: replacing a pending Bitcoin payment
FactDetailSource
ConflictThe replacement competes for an input already spent by the pending transaction.[3]
Transaction IDChanging the signed transaction normally creates a different transaction ID.[4]
PolicyBIP-125 documents historical opt-in policy; actual node rules depend on implementation and version.[1][3]
01

What gets replaced

A wallet starts with the payment it already created and prepares another spend of the same coins. It may reduce a change output or choose additional inputs to pay the extra fee. The replacement must still satisfy signatures, input availability and the receiving node’s relay rules.

The recipient should follow the replacement transaction rather than assume the original identifier must eventually confirm. Two conflicting transactions cannot both spend the same output in one valid accepted chain.

02

A fee increase in numbers

For illustration, a 140-vbyte payment at 5 sat/vB pays 700 satoshis. If its replacement remains 140 vbytes and uses 10 sat/vB, its fee is 1,400 satoshis. The additional 700 may come out of change. A changed input or output set can change the size, so a wallet must recalculate.

Paying more does not reserve a place in a block. Miner selection, node policy, conflicts and subsequent fee conditions still matter.

03

What to inspect before replacing

Check the recipient output, total fee, replacement identifier and whether the original has already confirmed. The cited Bitcoin Core 29.0 RPC describes its own wallet restrictions; these are not universal rules for every wallet.

BIP-125’s opt-in flag is useful historical context, but it must not be presented as an immutable consensus requirement for every replacement accepted by later software.

Direct answers

Questions people ask

Can RBF recover a payment that already confirmed?

No. A conflicting replacement is not a rollback of an accepted block. A confirmed payment would require a separate transaction from whoever can spend its output.

Inspect the evidence

The answer and key facts have stable claim links. These records retain the scope and qualification when reused.

Replace-by-fee, or RBF, submits a conflicting Bitcoin transaction that spends at least one of the same inputs, usually with a higher fee. The wallet must be able to construct it, and relay depends on receiving nodes’ policies. It cannot undo a payment already confirmed in the accepted chain.

Scope: Bitcoin · data through 2026-10-02. Verification: verified · 2026-10-02T18:15:23.891Z.

Link to this claim
Conflict: The replacement competes for an input already spent by the pending transaction.

Scope: Bitcoin · data through 2026-10-02. Verification: verified · 2026-10-02T18:15:23.891Z.

Link to this claim
Transaction ID: Changing the signed transaction normally creates a different transaction ID.

Scope: Bitcoin · data through 2026-10-02. Verification: verified · 2026-10-02T18:15:23.891Z.

Link to this claim
Policy: BIP-125 documents historical opt-in policy; actual node rules depend on implementation and version.

Scope: Bitcoin · data through 2026-10-02. Verification: verified · 2026-10-02T18:15:23.891Z.

Link to this claim
Revision history
  1. — Initial Bitcoin encyclopedia entry at this permanent URL.
  2. — Added reusable claims, explicit source locators, and matching Markdown and JSON. This publishing change does not itself establish factual verification.

Source register

Sources and references

Retrieval dates and locators are recorded individually.
  1. Opt-in Full Replace-by-FeeBitcoin BIPs contributors

    Historical opt-in replacement signaling and replacement policy conditions.

    Locator: Summary; Implementation Details · Version / scope: BIP-125; immutable revision pinned in source URL · Retrieved: 2026-10-02T17:22:20.573ZOpen source
  2. bumpfee RPCBitcoin Core

    Wallet-assisted replacement and the required fee and transaction conditions.

    Locator: Arguments and result fields · Version / scope: Bitcoin Core 29.0.0 RPC · Retrieved: 2026-10-02T17:03:40.979ZOpen source
  3. Bitcoin Core replacement policyBitcoin Core

    Implementation-specific replacement fees and conflict constraints.

    Locator: GetEntriesForConflicts; PaysForRBF · Version / scope: Bitcoin Core v29.0 · Retrieved: 2026-10-02T17:03:40.829ZOpen source
  4. Bitcoin Developer Guide: TransactionsBitcoin developer documentation contributors

    UTXO inputs, transaction outputs, change and the difference paid as a fee.

    Locator: P2PKH Script Validation; Transaction Fees And Change · Retrieved: 2026-10-02T17:03:41.190ZOpen source
  5. walletcreatefundedpsbt RPCBitcoin Core

    Input selection, fee units, change output, selected inputs and transaction funding.

    Locator: Arguments and result fields · Version / scope: Bitcoin Core 29.0.0 RPC · Retrieved: 2026-10-02T17:03:40.827ZOpen source
How this article was made

Research and drafting use AI assistance. A separate automated review checks claims against primary sources; no external expert or named human review is implied. Publication, substantive editing, source retrieval and verification are recorded separately. This version was independently checked by an automated reviewer on 2 October 2026.

Editorial method and corrections

Degrees of Satoshi editorial project. “Replace-by-fee: replacing a pending Bitcoin payment.” Published 2026-10-02; updated 2026-10-02. https://degreesofsatoshi.com/encyclopedia/replace-by-fee/