South Korean cryptocurrency exchange Bithumb, one of the country's largest crypto trading platforms, has won first-instance rulings in two of four lawsuits it filed against its users to recover proceeds from Bitcoin it mistakenly credited to their accounts.

The Seoul Central District Court ruled in Bithumb's favor on Wednesday and Thursday in two of the four suits brought against users who sold the mistakenly credited Bitcoin, according to a Chosun Biz report. Thursday's judgment concerned a claim for 194 million won ($140,000), while Wednesday's covered a claim for 5 million won ($3,600). Two further lawsuits — seeking approximately 14.8 million won ($10,700) and 500 million won ($362,000), the largest single claim in the group — remain pending, and the two decided judgments, as first-instance decisions, are subject to appeal.

Both decided cases proceeded through service by public notice because court documents could not be delivered to the defendants through ordinary methods, the report said.

The rulings advance Bithumb's effort to recover funds tied to its February error, when the exchange mistakenly credited 620,000 BTC — worth more than $40 billion at the time — to customer accounts.

Bithumb pursues Bitcoin sale proceeds

According to Bithumb, the error occurred during a promotional event on Feb. 6, 2026. The exchange had planned to distribute 620,000 won, about $420 at the time, in rewards to 249 users, but an employee mistakenly selected Bitcoin instead of Korean won as the payment unit and credited customer accounts with 620,000 BTC.

The exchange subsequently said it recovered 618,212 BTC, or 99.7% of the mistakenly credited amount. However, some users had already sold 1,788 BTC of the credited balances before Bithumb froze the affected accounts.

In March, Bithumb filed four unjust enrichment lawsuits — civil claims to recover benefits transferred by mistake that a recipient has no legal ground to keep — against users who sold the mistakenly credited Bitcoin and did not return the proceeds. The company was reportedly seeking cash from those sales rather than Bitcoin.

FSS opens sanctions process over the error

South Korea's Financial Supervisory Service (FSS) investigated Bithumb over the Feb. 6 Bitcoin error, focusing on how the exchange could credit customers with Bitcoin it did not hold. That question intersects with custody rules in place since 2021, when South Korea began requiring registered crypto exchanges to store customers' virtual assets separately and keep at least 90% of them in cold-storage wallets. The regulator reportedly sent Bithumb an inspection opinion in early August, formally beginning sanctions proceedings, but no final penalty has been announced.

Cointelegraph approached South Korea's Financial Services Commission (FSC), which oversees the FSS, for an update on the investigation and potential sanctions against Bithumb but did not receive a response by the time of publication.

Bithumb has faced other legal scrutiny this year. South Korean police raided its offices in June as part of an unrelated investigation into alleged hiring favoritism involving lawmaker Kim Byung-ki, while the company is challenging a separate six-month partial business suspension over Anti-Money Laundering violations. A Seoul court stayed the suspension in April pending a ruling on Bithumb's challenge.