Ofcom investigates BT and Three for failing to connect 999 calls

Ofcom is investigating BT and Three over mobile phone outages that they say have caused “UK-wide disruption”, including to emergency services.

Thousands of three clients reported that they could not make calls in Junewhile BT and EE customers were suffered a similar outage in July.

The regulator said it would examine whether mobile networks did not do enough to prevent problems.

Three said in a statement that it was cooperating with Ofcom. A BT Group spokesman apologized to affected customers.

“We will co-operate fully with Ofcom throughout the investigation and once again apologize for any issues caused by this incident,” they said.

Meanwhile, Three said it “experienced disruption to voice services following a surge in network traffic caused by a configuration change in third-party software.”

“We have been openly cooperating with Ofcom since the outage and will continue to cooperate fully with their investigation,” it said.

Ofcom said businesses should take appropriate steps to identify risks and prepare for anything that could compromise the availability, performance or functionality of their network or service.

It said suppliers must also prevent “adverse consequences arising from any such trade-offs,” saying that if they do occur, they must take steps to mitigate them.

“The importance of connectivity cannot be underestimated,” said telecommunications analyst Paolo Pescatore.

“We all need strong, reliable connections at home and outdoors.”

He said outages could happen despite “considerable efforts” to prevent them, but said there should be a “simple process for identifying the problem and learning lessons so it doesn't happen again.”

The incidents, which formed the basis of an Ofcom investigation, have led to thousands of BT and Three customers reporting problems with their mobile services.

Then on June 25, Three told customers who had complained about problems making and receiving calls that it had “an issue affecting voice services.”

This wasn't isolated to its own network – it was also causing problems for customers on networks that use Three, such as ID Mobile.

A month later, EE and BT customers complained of similar problems.

A government spokesman said at the time that “communications providers have a statutory obligation to ensure their networks and services are sufficiently resilient.”

In the past, operators have faced scrutiny for outages or problems affecting people's ability to make calls or access emergency services.

BT was fined £17.5 million in July 2024 for a “catastrophic failure” of its emergency call service that left thousands of 999 calls unconnected.

There were three ordered to pay £1.9 million in 2017 after Ofcom found it could have prevented the problem that led to customer service being cut off a year earlier.

It has since merged with Vodafone to form the UK's largest mobile network, with 27 million customers.