The US Commodity Futures Trading Commission (CFTC) ordered Interactive Brokers to payout more than $1m over failures to supervise its employees’ handling of exchange fees they charged customers, the agency announced on Thursday.

From January 2015 until at least December 2021, Interactive Brokers was found to have ‘failed to supervise diligently’ how their employees charged customers executing specific spread trades, paying out exchanges a lower amount while billing its customers improperly, the CFTC said in an order.

Interactive Brokers had charged fees applicable to outright trades rather than a lower rate the group charged for spread trades of equities futures and foreign exchange futures on the Chicago Mercantile Exchange (CME) Globex platform, according to the CFTC.

The firm is alleged to have overcharged customers a total of $710,828 over the roughly six year-period, violating the Commission’s rules on properly overseeing employees.

Interactive Brokers failed to notice the excessive charges for six years until the CFTC asked about them, the order said.

Investors transacting business through exchanges pay fees for trading and clearing trades which can vary in amount depending on a number of factors including rates, surcharges, fee structures, etc.

Charges against Interactive Brokers were settled the same day and the CFTC noted the firm had refunded affected customers and notified them of the overcharges.

The firm was also ordered to payout $300,000 in monetary penalties.

A spokesperson for Interactive Brokers did not immediately respond to a request for comment.

The CFTC’s action is the latest regulatory action taken against the firm related to supervisory failures.

In mid-2020, Interactive Brokers was slapped with a total $38m fine over anti-money laundering and reporting violations from a trio of regulators including the Financial Industry Regulatory Authority (Finra), the CFTC and the Securities and Exchange Commission (SEC).

Last year, the Wall Street Journal reported that the firm was also the subject of federal scrutiny for having done business with a Venezuelan who was investigated by authorities for money laundering.