O2 (UK) sale units, and with handset manufacturers, such as Apple and Samsung, to enable NFC technology on all future devices. On 23 February 2011, O2 announced it would launch a "second phase" for O2 Money, by discontinuing its branded cash cards in favour of a "mobile wallet" application for Android and iOS devices. The application would use NFC technology embedded in a phone to access money. It was announced on 9 January 2014 that the O2 wallet service would close on 31 March 2014. The BT Cellnet consumer brand was renamed O – the chemical symbol for an oxygen molecule –
O2 (Ireland) available to customers paying similar amounts in the UK. Less than 48 hours after the much hyped launch of Apple's latest model, owners of all phones on the O2 network discovered they could not access the internet at all due to a network failure. Further criticism came from iPhone customers regarding the continued failure of O2 to deploy Visual Voicemail. O2 was the only carrier in the world to launch the original iPhone without Visual Voicemail, one of its headline features. O2 was responsible for the highest number of registered judgments, which financially blacklists those people who do not pay