Ofcom said UK telecom operator Three is facing a penalty of £1.9 million for its failure in offering emergency call service to mobile phone users.

Ofcom, which conducted an investigation for finding a weakness in the mobile operator’s emergency call network, said the mobile operator failed to ensure customers could contact emergency services at all times.

Ofcom expects providers’ emergency call services to be sufficiently resilient. This includes ensuring their networks are built to allow emergency calls to be connected, even when they experience technical problems.

On 6 October 2016, Three notified Ofcom of a temporary loss of service affecting customers in Kent, Hampshire and parts of London.

Ofcom investigation found that emergency calls from customers in the affected area had to pass through a particular data centre in order to reach the emergency services. This meant that Three’s emergency call service was vulnerable to a single point of failure.

Three’s network should have been able to automatically divert emergency calls via back-up routes in the event of a local outage. These back-up routes would also have failed because they were directed through this one point.

Three added an additional back-up route to carry emergency call traffic to resolve the incident and address the underlying network weakness.

The penalty incorporates a 30 percent reduction to reflect the co-operation offered by Three during the investigation, including admitting the breaches identified by Ofcom.

“Telephone access to the emergency services is extremely important, because failures can have serious consequences for people’s safety and wellbeing,” said Gaucho Rasmussen, Enforcement and Investigations Director at Ofcom.