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
PageOne Communications PageOne Communications PageOne is a British Messaging Solutions company based in Brentford, London. For over 25 years PageOne have provided tailored and bespoke messaging and communications services. PageOne also operate one of the largest public paging networks in the UK. PageOne also provide: PageOne was the first paging operator in Europe to use satellite links for the distribution of pager messages, the first company to forward emails to pagers, the first to launch 'Calling Party pays' Pagers and helped pioneer the use of SMS technology as part of organisational communications. As of 2009, PageOne is the first and only organisation