Ofcom Investigates BT and Three for Mobile Network Outages
Summary
Ofcom has launched investigations into BT and Three following mobile network outages in summer 2025 that disrupted UK-wide mobile call services, including emergency calls. The investigations will assess whether the companies complied with their regulatory obligations regarding network availability and reporting.
What changed
Ofcom, the UK's communications regulator, has initiated investigations into BT and Three concerning significant mobile network outages that occurred in July and June 2025, respectively. These incidents caused widespread disruption to mobile call services, impacting the ability of customers to reach emergency services. The investigations will determine if BT and Three failed to meet their regulatory obligations, which include taking appropriate measures to prevent and mitigate network compromises and reporting outages above certain thresholds.
Telecommunications firms operating in the UK must ensure the availability, performance, and functionality of their networks and services, including robust measures to prevent adverse effects and timely reporting of significant incidents. Companies found to be in breach of these obligations may face regulatory action. This development underscores the critical importance of network resilience and compliance with reporting requirements for all mobile operators, particularly concerning the integrity of emergency call services.
Source document (simplified)
Ofcom investigates BT and Three following mobile network outages
Phones and broadband Telecoms infrastructure News and updates News Published:
15 December 2025 Ofcom has today launched investigations into BT and Three following outages in the summer that resulted in UK-wide disruption to mobile call services, including to emergency services.
Mobile operators are required to take appropriate and proportionate measures to identify and reduce the risks and prepare for the occurrence of anything that compromises the availability, performance or functionality of their network or service.
Providers must also take appropriate and proportionate measures to prevent adverse effects arising from any such compromises. Where there is an adverse effect on the network or service, the provider must take appropriate and proportionate measures to remedy or mitigate that effect.
Companies are legally obliged to report outages to Ofcom above certain thresholds.
BT has notified Ofcom of a software issue that resulted in a UK-wide disruption to mobile call services interconnecting to and from the EE network on 24 and 25 July 2025. This resulted in BT and EE customers being unable to make or receive mobile calls to other networks and emergency services.
Separately, Three has notified Ofcom of an incident that resulted in a UK-wide disruption to call services on 25 June 2025, including customers’ ability to contact emergency services.
Our investigations will seek to establish the facts surrounding these incidents and asses whether there are reasonable grounds to believe that BT and Three have failed to comply with their regulatory obligations.
Related content
### Ofcom fines Vonage £700,000 for emergency call failures
Ofcom has today fined communications provider Vonage £700,000 for failing to ensure certain business customers could make calls to the emergency services ### Ofcom opens investigation into IX Wireless
Ofcom has today opened an investigation into IX Wireless relating to its compliance with the Electronic Communications Code (ECC). ### Ofcom fines Gigaclear £122,500
Ofcom has fined broadband network provider Gigaclear £122,500 for failing to provide accurate and reliable caller location information to emergency services.
Related changes
Source
Classification
Who this affects
Taxonomy
Browse Categories
Get Government alerts
Weekly digest. AI-summarized, no noise.
Free. Unsubscribe anytime.
Get alerts for this source
We'll email you when Ofcom News Centre publishes new changes.