Über O2 UK

O2 UK traces its origins to BT Cellnet (1985). Telefónica acquired O2 in 2005, and in 2021 it merged with Virgin Media UK to form Virgin Media O2, a 50/50 joint venture between Liberty Global and Telefónica.

O2's standout metric is 5G availability in London: Opensignal records O2 at 77.8% - the highest of any UK operator. Network capacity is strongest in central London, with significant rollout across the south-east and major cities.

SIM-only plans start from GBP 15/month with 25 GB of EU roaming included - the most generous EU bucket among the UK Big Four. The standout consumer benefit is Priority, the loyalty programme that gives 48-hour pre-sale ticket access to The O2 arena and other AEG venues. O2 Open is the employer discount programme offering 10-20% off SIM-only for staff at participating companies.

O2 hosts MVNO traffic for giffgaff, Tesco Mobile, and Lyca Mobile in the UK.