Bitcoin miner AntPool will refund a record-breaking $3 million transaction fee paid in error last week, once it has verified the owner.

In an announcement, AntPool noted that its risk control system "temporarily froze the fee when packaging the transaction," and invited the user to verify themselves before December 10.

AntPool requested that the individual who sent the funds prepare a signing tool, either Electrum or Bitcoin Core, and use the private key of the address that sent the transaction to sign the message "AntPool" before sending the signed text to the AntPool support email address.

The record-breaking transaction was sent last week, in block 818087. The sender indended to send 139.42 BTC (then worth around $5.1 milion) of which 83.64 BTC was spent on transaction fees. The receipient was left with just 55.77 BTC, worth around $2 million.

It's not the first time that an outsized Bitcoin transaction fee has been refunded recently. In September, Bitcoin miner F2Pool agreed to refund a $500,000 transaction fee paid by crypto firm Paxos to process a transaction worth just $2,000.

Although the $3 million transaction fee was the product of a mistake, Bitcoin transaction fees have increased in the past month, with data from Ycharts indicating that the average transaction fee is now $6.7 versus $1.15 at the end of October, a more than five-fold increase.

Earlier in November the average transaction fee spiked as high as $18, as hype surrounding Bitcoin Ordinals generated more activity on the network. Ordinals are digital assets akin to non-fungible tokens (NFTs) that are inscribed on a satoshi, the lowest denomination of a Bitcoin.

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