Bitcoin News Today: Developer rkrux opened Bitcoin Core PR #35405 and posted it to the Bitcoin-Dev mailing list on June 19, 2026, proposing to strip the old Replacement Fee (RBF) flag from wallet transactions, arguing that the BIP125 flag has become a redundant on-chain identifier now that full RBF is the network’s virtual memory pool policy.
This is not just code cleaning. It is a coordinated privacy initiative for Bitcoin that requires cross-wallet alignment on a single virtual nSequence value, which is a more structurally complex problem than removing the flag.
rkrux posted to the Bitcoin-Dev mailing list suggesting that wallets stop indicating subscription to RBF in the transactions they create…https://t.co/djmBbIubDG
— Bitcoin Optic (@bitcoinoptech) June 19, 2026
Bitcoin News Today: RBF Signal Removal: Why Outdated Science Now Creates More Risks Than It Solves
under Pep125a transaction was considered to have been selected for replacement if any entry had an nSequence value below 0xffffffff − 1, A mechanism introduced in Bitcoin Core 0.12.0 in February 2016 to enable voluntary raising of fees for unconfirmed transactions without disrupting the behavior of the memory pool was first seen across the network.
Bitcoin Core’s subsequent switch to full RBF as the default policy began with mempoolfullrbf The option was added in version 24.0 and later set as an unconditional default, making that signal operationally inactive. As rkrux stated in the mailing list post: “The main reason for removing it is that since the full RBF policy has become a standard policy, this flag has become redundant.” Nodes running with the current default policy will replace any transaction regardless of their nSequence values RBF Topic Documentation for Bitcoin Optech.
The decade-old Bitcoin transaction token became a dead token 20 months ago. Bitcoin Core contributor rkrux wants wallets to stop assigning them. The reason is privacy
Fee redemption allows you to raise the fees for a parked Bitcoin transaction after it has already been broadcast. Subscribe to BIP 125… pic.twitter.com/CvIlt3vQqa
– Taurus (@Taurus4BTC) June 22, 2026
The remaining cost of retaining the signal is wallet fingerprinting. Since the nSequence field is mandatory, wallets cannot leave it blank, and any wallet that removes the BIP125 flag without formatting to an alternative value will produce transactions with a distinct sequence pattern, making them identifiable on-chain. This concern is directly similar to the on-chain tracking patterns that emerge in analysis of long-term owner behavior, where Portfolio-level metadata leakage informs course placement Far beyond what the participants intend to reveal.
Serial Number Format: MAX-2 status as the default ecosystem
Community participant Murch, identified in Optech coverage as Gloria Chow, described the underlying tension: “Stopping to replace a signal makes it seem like it’s a matter of dropping a fingerprint, but…each sender has to choose a sequence for each entry.” The field must have a value; The question is what value all portfolios converge to.
Both Murch and SomberNight developer Electrum preferred to use MAX-2 as the standard default value, a position reinforced by Optech data showing that MAX-2 is already the dominant nSequence value across about 75% of Bitcoin transactions.
Switching to MAX-1 – a non-signal value – was considered, but set aside because it would make Bitcoin Core transactions visually distinct from the existing majority, creating a new fingerprint rather than removing one. The goal, as rkrux puts it, is for the broader wallet community to agree on “what the broader wallet community has agreed upon as best practice.”
🔴Bitcoin developers move to strip RBF signals, citing privacy and redundancy leaks
Bitcoin developers are coordinating to remove Replace Fee (RBF) signals from the wallet software. The explicit subscription tag became redundant after the network adopted the full RBF as standard… pic.twitter.com/SRsQQMhk3v
– NewsTongue (@NewsTongueX) June 22, 2026
There is also a rationale for future compatibility. A proposed future upgrade to nVersion = 3 transactions with RBF package semantics would retain MAX and MAX-1 for distinct policy behavior, making MAX-2 the more secure default in the long term and reducing migration friction as these changes roll out.
Industry Implications: Conf-less trader workflow and shared wallet scope
This change maintains full charging ability for users, and the ability to replace an unconfirmed transaction with a higher-fee version will not be affected. What changes is the visibility of this choice in the transaction structure itself. A merchant workflow that previously used a visible BIP125 opt-in sign as a proxy risk signal to accept zero confirmation transactions will have to treat all unconfirmed transactions as policy replaceable, which is the exact technical position since full RBF has become the default.
We believe the most important finding is the precedent for cross-portfolio coordination. If Bitcoin Core consolidates PR and final wallets through consolidation on MAX-2, this episode will represent one of the most structured ecosystem-level alignments of defaults in recent Bitcoin development, in contrast to the fragmented rollout of the full RBF itself, which continued wallet by wallet over several years before network-level coherence was achieved.
Disclaimer: Coinspeaker is committed to providing unbiased and transparent reporting. This article aims to provide accurate and timely information but should not be considered financial or investment advice. Since market conditions can change rapidly, we encourage you to verify the information yourself and consult with a professional before making any decisions based on this content.
Daniel Francis is a technical writer and Web3 educator specializing in macroeconomics and DeFi mechanics. A crypto native since 2017, Daniel brings his background in cross-chain analytics to author evidence-based reports and detailed guides. It is certified by the Blockchain Council and is dedicated to providing “information gain” that cuts through the market noise to find blockchain’s real-world utility.
