The popular Bitcoin exchange Coinbase was reported to be overcharging some customers thousands of dollars throughout early February. The problem caused many customers to be charged multiple times for the same transactions, but some customers also reported seeing unauthorized withdrawals, reversed transactions, and other unexplained fees on their accounts. While the problem has now been fixed, Coinbase disclosed that the fault stemmed from card issuer Visa. It was initially reported that the error was caused by recent changes in the merchant category code, or MCC that Visa uses to identify credit and debit card transactions and classify digital currency transactions.As a result of the issue, customers who purchased cryptocurrencies between January 22nd 2018 and February 11th 2018 using credit or debit cards may have been overcharged, had their purchases wrongly refunded or reversed, or reprocessed more than once, resulting in the same transaction being charged several times. In response to the overcharging problems, Visa issued a statement confirming that the issue was not caused by Coinbase. However, the company also stated that they made no changes or reclassifications to existing MCC codes, which still leaves customers in the dark as to what underlying cause triggered the payment problems. While a temporary fix for the overcharging issue is in place, it doesn’t appear that any long-term solution has yet been discovered. Coinbase announced in a statement that they are working with card networks in the hopes of creating a new MCC for digital currency purchases. The cryptocurrency exchange continues to work closely with banks, payment processors and other networks in an effort to improve each customer’s digital currency purchasing experience. Coinbase also released a statement ensuring that any affected customers will receive full refunds for any charges made in error. However, the company also confirms that some customers may experience a delay between seeing the corrected new charge and any refund due on their accounts.