BT has been fined more than £17m for missing 14,000 emergency calls after technical faults caused the emergency call handling service to be disrupted for nearly 11 hours last summer.

The telecoms regulator launched an investigation shortly after the incident on 25 June 2023. Publishing its findings on Monday, Ofcom said the handling of the network fault was a “catastrophic failure”.

The watchdog’s director of enforcement, Suzanne Cater, said: “Being able to contact the emergency services can mean the difference between life and death, so in the event of any disruption to their networks, providers must be ready to respond quickly and effectively.

“In this case, BT fell woefully short of its responsibilities and was ill-prepared to deal with such a large scale outage, putting its customers at unacceptable risk.

“Today’s fine sends a broader warning to all firms: if you’re not properly prepared to deal with disruptions to your networks, we’ll hold you to strict account on behalf of consumers.”

BT, which manages the emergency services calls system, said it had taken three days to contact each of the callers who had not been connected after what it described as a complex software problem that affected nearly 14,000 call attempts from 12,392 people.

“Being able to contact the emergency services can mean the difference between life and death,” Cater said. “So in the event of any disruption to their networks, providers must be ready to respond quickly and effectively.”

Ofcom said its decision to fine BT £17.5m was based on a number of factors including the seriousness, duration and degree of harm.

The regulator found BT had neither sufficient warning systems in place for this kind of incident nor adequate procedures for quickly assessing the severity, impact and likely cause of such a software failure.

It also found the telecoms company’s disaster recovery platform had insufficient capacity and functionality to deal with a level of demand that might be reasonably expected.

“Although there have been no confirmed reports by the emergency authorities of serious harm to members of the public as a result of the incident, the potential degree of harm was extremely significant,” Ofcom said.

BT apologised for the technical failure, saying it takes “great pride” running the 999 service and had fallen “short of our own high standards” in this case.

A BT spokesperson said: “The level of disruption to the service on Sunday 25 June last year has never been seen before and we are sincerely sorry for the distress caused.

“While no technology is 100% resilient, we have built a highly robust network with multiple layers of protection to connect the public to blue light services in their time of need. We take our responsibility to the emergency services and the public seriously, and on this occasion we fell short of our own high standards for the 999 service.”