T-Mobile reported its first quarter 2013 earnings on Wednesday. The carrier, which recently finished its acquisition of MetroPCS, noted a 7.5-percent revenue slip from the same quarter in 2012 to $1.2 billion primarily due to declines in service revenues. T-Mobile currently serves 34 million customers in the United States, up 579,000 customers from the fourth quarter of last year. Still, it noted that it lost 199,000 postpaid customers during the quarter.

T-Mobile also noted that it has sold 500,000 iPhone 5 units since the device went on sale in April, although those sales are not reflected in the quarterly report, which represents a three-month period ended March 31.

"Our first quarter operating metrics and financial results are showing positive impact from the changes we began making in the fourth quarter. Branded customer net additions turned positive for the first time since the first quarter of 2009 and our postpaid business has demonstrated significant improvement," T-Mobile president and CEO John Legere said. Legere also noted that T-Mobile's "uncarrier" plans have been successful so far and that things will only get "more exciting from here."