The Bitcoin miner AntPool is refunding a $3,000,000 transactional fee it paid last week. This was due to a user error that likely led to the largest fee ever paid for a Bitcoin transfer.

In a announcement on Thursday, AntPool stated that “On November 23, some users submitted BTC 83 as a fee for gas.” The risk control system at ANTPOOL temporarily frozen the fee during the packaging of the transaction.

The miners use massive computing power to process transactions in blockchains, such as Bitcoin. They receive a reward for each “block” they mine successfully.

The miners are not required to refund fees but they may do so if the amount is unusually high.

AntPool will verify ownership if the sender signs an on-chain bitcoin message using another transaction that uses the same message.

On-chain data indicates that AntPool was paid the standard 6.25 Bitcoin (BTC) last Thursday as well as 85.2163 BTC for all transactions in this erroneous transfer. On-chain data shows that the sender set up his wallet just minutes before transferring the money, but the recipient only received 55.78 BTC out of the 139.42 BTC originally sent.

Oliver Knight is the editor.