BT and Three face Ofcom probe over mobile outages disrupting 999 calls

Ofcom has launched an investigation into BT and Three following significant mobile network outages that left thousands of customers without access to essential call services, including emergency numbers. The review comes after multiple disruptions during the summer, raising concerns regarding the reliability and preparedness of leading UK telecoms providers.

BT notified the regulator that a software fault affected its EE network on 24th and 25th July 2025, preventing customers from making or receiving calls to other networks, including calls to the emergency services. Three experienced a similar issue on 25th June, when an exceptional traffic spike, triggered by a third-party software configuration change, disrupted voice services.

Ofcom’s rules require telecoms companies to take reasonable measures to protect customers from major outages and to report any incidents above defined thresholds. The regulator will assess the circumstances around both incidents to determine if BT and Three failed to uphold their obligations and to protect users’ ability to reach emergency services.

BT has stated it will cooperate fully with the investigation and apologised for the inconvenience caused. Three confirmed it is working with Ofcom, affirming its commitment to transparency.

Critical scrutiny of the sector has intensified due to the consequences of recent outages. In June 2023, BT faced a £17.5 million fine after a 10.5-hour blackout affected almost 14,000 emergency calls. Ofcom determined BT was not adequately prepared for a failure of its emergency call-handling service, which underpins the 999 and 112 networks nationwide.

Three was fined £1.9 million in 2016 for an outage impacting emergency calls in several parts of the country. Vonage, owned by Ericsson, received a £700,000 penalty for similar failings in September.

These events highlight the critical importance of resilient telecoms infrastructure. As technology grows increasingly complex and central to public safety, effective regulatory oversight and robust systems remain essential to ensuring that emergency services are always accessible to the public.