T-Mobile USA is a cellular telecommunications provier and the United States based subsidiary of T-Mobile International AG, itself based in Bonn, Germany. The US company was previously known as VoiceStream Wireless or Powertel. In May 2001, VoiceStream was acquired by Deutsche Telekom for US$24 billion, and in September 2002 changed the company name nationally to T-Mobile. Headquartered in Factoria, Bellevue, Washington, T-Mobile USA is currently the fourth-largest wireless carrier in the U.S. market with 30.8 million customers as of the end of the first quarter 2008 and annual revenue of US$17.1 billion for their 2006 fiscal year