On Thursday, December 2, 2023, millions of mobile phone users in the UK experienced problems with making and receiving voice calls across different networks. The issue affected customers of EE, O2, Vodafone and Three, as well as other smaller operators that use their infrastructure. Many users reported that their calls were failing or dropping out, while others said they could not connect to certain numbers at all.
The outage started around 10:30 am GMT and lasted for more than an hour, causing frustration and inconvenience for many people who rely on their phones for work, education and socialising. Some users also complained about poor customer service and lack of communication from their network providers.
What caused the outage?
The exact cause of the outage is still unclear, but some experts have suggested that it could be related to the ongoing transition from 3G to 5G technology in the UK. Mobile network operators, including Vodafone, EE and Three, have begun phasing out 3G mobile services across the UK, as part of a wider industry initiative to switch off 3G and 2G by 2033. This means that some older devices and SIM cards that rely on 3G may not be compatible with the newer 4G and 5G networks, leading to connectivity issues.
Another possible explanation is that there was a fault in the interconnection system that allows different networks to communicate with each other. This system, known as the Public Switched Telephone Network (PSTN), is a complex network of cables, switches and routers that connects phone calls across the world. If there is a problem with any part of this system, it can affect the quality and reliability of voice calls.
How did the networks respond?
The network operators acknowledged the outage and apologised to their customers for the inconvenience. They also said that they were working to resolve the issue as soon as possible and restore normal service. Some of them also offered compensation or refunds to their affected customers, depending on their terms and conditions.
EE, which is owned by BT Group, said that the issue was caused by a third-party supplier and that it had no impact on its mobile data or broadband services. O2, which is owned by Telefonica, said that the issue was caused by a problem with EE’s network and that it affected voice calls to and from EE customers. Vodafone said that the issue was caused by a technical fault and that it affected voice calls to and from other networks. Three said that the issue was caused by a network interconnect problem and that it affected voice calls to and from other networks.
What can customers do?
Customers who experienced the outage can check their network’s website or social media accounts for updates and advice on how to deal with the issue. They can also contact their network’s customer service team to report any problems or request compensation or refunds. Customers who are still experiencing problems with their voice calls can try the following steps to troubleshoot the issue: