*Connections are defined as the number of Subscriber Identity Modules (SIMs) classed as active in the last 90 days. No.1 Network: Based on total number of connections to O2 network vs. number of connections to each of, Vodafone, BT Group, and Three as of 30.06.20. Limitations to network coverage and terms apply. Ranking by MNO based on number of connections:
1. Telefonica UK
2. BT Group
For further information, please see our terms and conditions.
**Institute of Customer Service Index Customer Satisfaction rankings [Jan 2020].