O2 (UK) O2 (UK) Telefónica UK Limited (trading as O2 – stylised as O) is a telecommunications services provider in the United Kingdom, owned by the Spanish multinational Telefónica, and is headquartered in Slough. With 25 million subscribers (as of December 2017), O2 is the second-largest mobile network operator in the United Kingdom after EE, with Vodafone in third place. O2 was formed in 1985 as Cellnet, a 60:40 joint venture between BT Group and Securicor. In 1999, BT Group acquired Securicor's share of Cellnet and the company was later rebranded as BT Cellnet. In June 2000, BT Cellnet launched the world's
O2 Money to recognise "customer service, excellence and innovation" in the UK and Irish payment industry, O2 won the Best New Prepaid Card Product of the Year and Best Prepaid Card Marketing Campaign of the Year awards, receiving judges were particularly impressed with the concept of the card. O2 Money was critically praised at the event, particularly in regard to the high profile, customer-centric campaign used to promote the service for "[blowing] away the cobwebs surrounding payment cards and [lifting] the stigma of prepaid as a product for low-income consumers." Additionally, the judges at the event were thankful to O2 for helping