According to a mempool developer, the person behind the transfer may have been unaware of the non-cancellation of replacement costs policy, resulting in an unintentional $3.1 million transaction fee. A Bitcoin user spent 83.7 Bitcoin in transaction fees (worth $3.1 million) for transferring 139.42 BTC. The $3.1 million transaction fee is the eighth-highest in Bitcoin’s 14-year history.
On November 23, the BTC wallet address bc1qn3d…wekrnl attempted to send 139.42 BTC to bc1qyf…km36t4, only to pay more than half the transaction fee. Only 55.77 BTC were sent to the recipient’s address. Antpool, a mining pool, captured the outrageously high mining fee on block 818087. Users on social media speculated that the sender chose the high transaction cost, but the replace-by-fee (RBF) node policy and the sender’s ignorance appear to have also played a role. RBF enables an unconfirmed transaction in the mempool to be replaced with a different transaction that pays a higher transaction fee in order for it to be cleared sooner. All BTC transactions are queued in the mempool before being approved and added to the Bitcoin network.
According to a mempool developer known as mononaut on X (previously Twitter), the user who initiated the transfer was likely unaware that RBF orders cannot be cancelled. The user may have replaced the fees several times in the hopes of cancelling it. According to the RBF history, the most recent replacement increased the cost by another 20%, totaling 12.54824636 BTC in fees. This is not the first time that a Bitcoin user has submitted an excessively high transaction fee for a single Bitcoin transaction. Paxos, a Bitcoin exchange platform, erroneously sent a $500,000 transaction fee for a $2,000 BTC trade in September. In that case, the F2Pool miner who validated the transaction reimbursed Paxos for the $500,000 unintentional transaction cost.
However, this is the highest BTC transaction fee ever paid in dollars, surpassing the $500,000 Paxos payment in September. In Bitcoin terms, the greatest fee was paid in 2016 when someone unintentionally transmitted 291 BTC in transaction fees. Although the current instance of an accidental transaction fee resembles the Paxos case, Mononaut told Cointelegraph that the possibility of Antpool returning the funds would depend on their own payout policies, “which might have implications for what obligations they have to share transaction fees with their miners.”