Nationwide 999 outage disrupts Public Emergency Call Service for a day

A complex software fault on BT's 999 platform disrupted the UK's Public Emergency Call Service (PECS) on Sunday 25 June 2023, the first nationwide loss of 999 in over 86 years since the service began in 1937¹. BT experienced a technical fault affecting its ability to transfer 999 calls to the emergency authorities¹. The Post-Incident Review records that a total of 9,641 unique callers were unable to access the emergency services via 999 or 112 during the incident, which ran from 06:24 to 16:56¹.

The review divides the incident into three phases, set out in the table below¹.

The review describes the cause as "a complex software issue related to a 'caching' mechanism used by the software for handling 999 emergency calls"¹. It states that 253 unique callers were not able to be contacted, and that BT assesses alternative PECS services provided to a very small number of customers, such as Video Relay, SMS and eCalling, may also have been affected¹. To date, there are no confirmed reports by the emergency authorities of serious harm done to members of the public as a result of the disruption, although the review says this will continue to be kept under review by those authorities¹.

The review records that the public were advised to use the non-emergency numbers 101 and 111 to seek emergency support from police and ambulance services respectively in the absence of 999, but notes this is not applicable for some parts of the UK such as Northern Ireland¹. It states that this advice was not released until approximately 15:45, when the government issued a statement to the media¹.

In 2022 the public made 35 million calls to the service, 53% of which were for an ambulance, 44% for police, 3% for fire and rescue and less than 1% for HM Coastguard¹. BT filters approximately 30% of calls, identified as repeat calls, misdials or nuisance callers¹. The review says the PECS partners make a total of 113 separate entities: 45 territorial police forces and 3 special police forces, 49 fire and rescue authorities and 14 ambulance service trusts¹.

Why it matters for households

The outage affected anyone in the UK who needed to reach police, ambulance, fire and rescue or HM Coastguard by dialling 999 or 112 on 25 June 2023, and the review states that many more calls were delayed or disrupted beyond the 9,641 who could not get through¹. During the denial phase, all callers failed to connect¹. During the delay phase, callers could get through but waits were longer because location and other details had to be processed manually¹. The review records that the public were advised by the authorities to use 101 for police and 111 for ambulance services while 999 was unavailable, and that this did not apply in some parts of the UK such as Northern Ireland¹. The review notes that the advice reached the public only at approximately 15:45, close to the end of the incident¹. Households can read about what happens on a call in Calling 999 and 112: What Happens When You Ring, when an emergency call is appropriate in When Should You Call 999?, and how to keep alternative numbers to hand in Emergency and Non-Emergency Numbers to Keep on Paper.

What happens next

The review records that, after collective agreement from all PECS partners on 17 July 2023, a nationwide 999 Strategic Incident protocol was established, and that a permanent software configuration fix was introduced by August 29, 2023¹. It also notes that Ofcom is conducting an independent investigation relating to compliance with its General Conditions of Entitlement and applicable sections of the Communications Act 2003, and that the review's findings will have no bearing on Ofcom's later findings¹. BT published its own report on the incident on 29 June 2023¹.