O2 Referral Code page. Welcome! Enjoy and shareO2 referral links on this page. Fan of O2? Make sure you give them a thumbs-up recommendation - influence friends, followers and others. O2 is a leading digital communications company with the highest customer satisfaction for any mobile provider according to O2. O2 has 25 million customers and runs 2G, 3G and 4G networks across the UK. ?