T-Mobile has to pay $40 million as part of a settlement after the FCC ruled that it violated the law by adding fake ringtones to hundreds of millions of calls over several years. It will also have to act within 90 days and send a compliance report to the FCC once a year for the next three years.

The carrier admitted to adding fake ringtones to make customers mistakenly believe the party they called was hearing their phones ring, when in fact the call might not have been connected yet. The FCC noted in a document, “A caller may then hang up, thinking no one is available to receive the call ... False ring tones are a problem on calls to rural areas and are a symptom of the problems of impaired quality and completion of calls to rural areas.”

In 2014, the FCC enacted an order to ban the practice of adding fake ringtones. Users began to complain that T-Mobile wasn’t complying with the ban, and the FCC launched an investigation into the carrier’s actions in response. T-Mobile then claimed it had removed fake ringtones, but users continued to complain until the FCC discovered the full extent of T-Mobile’s violations.