Ofcom targets BT and Three as summer outages exposed emergency call risk
The UK’s telecoms regulator has launched investigations into BT and Three after network failures this summer left customers unable to make calls, including to the emergency services.
Ofcom said on Monday that the probes will assess whether the two operators complied with their legal dutiesm after separate incidents caused nationwide disruption.
Telecoms giant BT notified the watchdog of a software fault that hit its EE mobile network on 24 and 25 July this year, preventing customers from making or receiving calls to other networks and, crucially, to 999.
Three separately reported a UK-wide outage on 25 June that also disrupted call services, including access to such emergency lines.
The regulator announced it will now “seek to establish the facts surrounding these incidents and assess whether there are reasonable grounds to believe that BT and Three have failed to comply with their regulatory obligations”.
A BT spokesperson said: “We are aware that Ofcom has begun an investigation into the technical fault impacting voice calls on our network on July 24 and 25 2025. We will co-operate fully with Ofcom throughout the investigation and apologise again for any issues caused by this incident.”
“Three experienced disruption to voice services following an exceptional spike in network traffic triggered by a third-party software configuration change. Since the outage, we have engaged openly with Ofcom and will continue to cooperate fully with their investigation,” said Three.
Emergency access in focus
Under British telecoms rules, operators have to take “appropriate and proportionate measures” to reduce risks to their networks, prevent service disruption, and limit har, when failures occur.
Where outages do happen, providers must act quickly to remedy or mitigate the impact – especially where emergency services are affected.
Ofcom said: “Mobile operators are required to take appropriate and proportionate measures to identify and reduce the risks, and prepare foe 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.”
The investigations follow a seperate Ofcom probe from earlier this year into BT, following disruption to the 999 service.
Meanwhile, this month, it handed Virgin Media a £23.8m fine over failure to protect vulnerable customers during a landline migration.
BT Group, which owns EE, serves over 30 million customers in the UK and reported revenues of £20.4bn in 2025.
The company has said the July fault was resolved and services were restored, but the regulator’s action underlines how seriously it views outages that affect public safety.
Ofcom said it would provide further updates once its investigations go through.