(Telecompaper) T-Mobile US reported another quarter of strong customer growth, adding a net 1.645 million new customers in the fourth quarter. Postpaid customers under its own brand grew by 869,000 in the three months, a 34 percent increase from the previous quarter. Over the full year 2013, T-Mobile added 2.0 million postpaid lines, more than its guidance of 1.6-1.8 million. The prepaid customer base grew by 112,000 in Q4, with growth held back by some 120,000 prepaid users switching to postpaid. The company also gained 664,000 wholesale lines in the quarter, including 172,000 M2M Sims. In total, T-Mobile had 46.684 million customers at year-end, up by 10.4 percent from a year earlier.