Users on T-Mobile US’ so-called unlimited plans unfairly ran into speed limits after using a certain amount of data, said the Federal Communications Commission.

The operator’s advertising may have led users on such plans to think they were getting better and faster services than they actually were, according to an FCC statement.

The settlement of at least $48 million includes a fine of $7.5 million in addition to $35.5 million in consumer benefits that the operator and subsidiary MetroPCS will offer to subscribers on unlimited plans, and a donation of at least $5 million in services and equipment to US schools.

The regulator said T-Mobile US had also “stepped up to the plate” by ensuring its users will now have the information they need about its unlimited plans.

Under its so-called Top 3 Percent Policy, the operator “deprioritises” heavy data users during network contention or congestion.

The regulator said T-Mobile US did not adequately inform users that data would be slowed at times if they consumed more than 17 GB in a month.

Under the settlement, the operator will update its disclosures to clearly explain to users what triggers its policy and its impact on data speeds. It is also required to tell individual users when their data usage approaches its limit. The company will also adopt the FCC’s Consumer Broadband Label to provide more clarity about service terms.

In terms of disclosures, T-Mobile US must either be clear about all restrictions on the amount and speed of data for unlimited plans; cease to use the term “unlimited” altogether to describer such plans; exclude unlimited data plans users from its Top 3 Percent Policy or similar practice; or limit any speed reductions for unlimited data customers to the minimum speed described for a particular plan.