Vodafone Group plc is a British mobile phone operator headquartered in Newbury, Berkshire, England. It is the largest mobile telecommunications network company in the world by turnover and has a market value of about $134 billion (June 2006). Vodafone currently has equity interests in 26 countries and Partner Networks (networks in which it has no equity stake) in a further 33 countries. At 31 March 2006 Vodafone had 170.6 million proportionate customers in 26 markets across 5 continents. ("Proportionate customers" means, for example, that if Vodafone has a 30% stake in a business with a million customers, that is counted as 300,000). On this measure it is the second-largest mobile telecom group in the world behind China Mobile. The six markets where it has more than ten million proportionate customers are the United Kingdom, Germany, the United States, Italy, Spain and Turkey. In the U.S., these customers come via its minority stake in Verizon Wireless, and in the other five markets Vodafone has majority-controlled subsidiaries.

Vodafone's portfolio of global services, supported by its global brand, is available in a total of 59 countries. In a historic deal, on 17 March 2006 Vodafone Group announced an agreement to sell its ownership of Vodafone Japan (Vodafone K.K.) to SoftBank. On April 14, 2006 SoftBank and Vodafone K. K. jointly announced, that the brand and company name Vodafone will be changed to a "new, easy-to-understand and familiar company name and brand". Masayoshi Son became CEO (Representative Director) of Vodafone K. K.
On 30 May 2006, the company announced a loss before tax of £14.9 billion ($27.9bn) for 2005, the biggest loss in British corporate history. The loss for the year from continuing operations was £17.2 billion and the bottom line loss for the financial year was £21.8 billion. The company was pushed into loss by impairment charges of £23.5 billion, which related to the acquisition of Mannesmann several years earlier, and losses of £4.6 billion in relation to its discontinued business in Japan. At an operating level it remained highly profitable, with an operating profit on continuing operations of £9.4 billion before impairment costs.