High Quality Content by WIKIPEDIA articles! Vodafone UK is a mobile telephone company, operating in the United Kingdom. Vodafone (UK) is currently the 3rd largest wireless operator in Britain, in terms of active subscribers, behind O2-UK, and Orange/T-Mobile (after their merger was announced in 2009).[citation needed] As Vodafone Group started and is established within the United Kingdom, please refer to this article for more details of the history of Vodafone within the UK.