The UK national terrorism threat level is
SEVERE
An attack is highly likely.
Raised from substantial on 30 April 2026. That was 154 days ago.
The separate threat level for Northern Ireland-related terrorism in Northern Ireland is substantial.
The threat level since 1968
Threat levels have been published since August 2006. Earlier years are shown as estimates based on attack activity and press reports at the time. Each dot marks a change. Hover, tap or tab to one for the details.
Since August 2006 the level has been severe or critical for 52% of the time. It has never been set to moderate or low.
Every change
Most recent first. Rows in grey italics are estimates, not official gradings.
| From | Level | Lasted | Context |
|---|---|---|---|
| Severe | 5 months so far | Raised after the Golders Green stabbing, reflecting a rising Islamist and extreme right-wing threat | |
| Substantial | 4 years, 3 months | Lowered as JTAC judged the threat was back to its level before the Amess murder and the Liverpool bomb | |
| Severe | 3 months | Raised after the Liverpool Women's Hospital bomb, the second UK attack in a month after the murder of Sir David Amess | |
| Substantial | 9 months | Lowered as the wave of attacks in Europe between September and November 2020 lost momentum; announced on 8 February | |
| Severe | 3 months | Attacks in France and Vienna | |
| Substantial | 12 months | Lowered after a routine six-monthly review, the first time below severe since 2014. The Fishmongers' Hall attack followed on 29 November | |
| Severe | 2 years, 2 months | Lowered after arrests in the Parsons Green investigation | |
| Critical | 2 days | Parsons Green Tube bombing | |
| Severe | 4 months | Lowered after police arrested a large part of the Manchester bomber's network; troops withdrawn from the streets | |
| Critical | 4 days | Manchester Arena bombing | |
| Severe | 2 years, 9 months | Rise of Islamic State and fighters travelling to Syria and Iraq | |
| Substantial | 3 years, 2 months | Lowered two months after the death of Osama bin Laden; the Home Secretary gave no specific reason | |
| Severe | 18 months | Raised after the failed Christmas Day 2009 bombing of a Detroit-bound airliner, amid increased intelligence about al-Qaeda planning; no imminent attack was indicated | |
| Substantial | 6 months | First drop below severe since threat levels were published; security sources called it a finely balanced judgement. No specific reason was given | |
| Severe | 2 years, 1 month | Lowered after suspects linked to the Glasgow and London attacks were arrested | |
| Critical | 4 days | Glasgow Airport attack and London car bombs | |
| Severe | 11 months | Lowered after the arrest of the main airliner plot suspects; airport security restrictions stayed in place | |
| Critical | 3 days | Transatlantic airliner liquid bomb plot | |
| Severe | 9 days | Threat levels published for the first time | |
| Severe (est.) | 12 months | After the July 2005 attacks | |
| Critical (est.) | 25 days | London bombings, then the failed 21 July attacks | |
| Substantial (est.) | 2 months | Press reports of a reduction under the internal system | |
| Severe (est.) | 3 years, 8 months | After 9/11; reported as “severe general” for several years | |
| Substantial (est.) | 15 months | Real IRA attacks: MI6 building 2000, BBC Television Centre and Ealing 2001 | |
| Moderate (est.) | 17 months | Low mainland activity | |
| Substantial (est.) | 17 months | Ceasefire restored; Good Friday Agreement in 1998 | |
| Severe (est.) | 17 months | Ceasefire ends with the Docklands bomb; Manchester bombed in June | |
| Moderate (est.) | 13 months | Ceasefire holding, little mainland activity | |
| Substantial (est.) | 4 months | IRA ceasefire | |
| Severe (est.) | 15 years, 5 months | Airey Neave murdered; sustained campaign through the 1980s and early 1990s, including Hyde Park, Harrods, Brighton, Deal, Warrington and Bishopsgate | |
| Substantial (est.) | 2 years, 3 months | Fewer mainland attacks | |
| Severe (est.) | 2 years | London bombing campaign by the Balcombe Street unit | |
| Critical (est.) | 41 days | Birmingham pub bombings, following Guildford and the M62 coach bomb | |
| Severe (est.) | 2 years, 9 months | Official IRA bombs Aldershot barracks; Provisional IRA mainland campaign begins with the Old Bailey in 1973 | |
| Substantial (est.) | 13 months | Angry Brigade bombings, including Robert Carr's home; Post Office Tower bomb in October | |
| Moderate (est.) | 17 months | The Troubles begin; troops deployed in Northern Ireland | |
| Low (est.) | 19 months | No sustained terrorist campaign in Great Britain |
About this site
The threat level is set by the Joint Terrorism Analysis Centre (JTAC), based at MI5. It reflects how likely an attack is, not whether one is expected on a particular day. Since July 2019 a single national level covers all forms of terrorism, whatever the ideology.
Before 2006 the government assessed the threat internally but did not publish it. The estimates here apply today's five-level scale to what is known about each period: the years before the Troubles, the Angry Brigade, the IRA's mainland campaigns of the 1970s to 1990s, the ceasefires, Real IRA attacks, the years after 9/11, and the July 2005 bombings.
This is an independent site. It is not affiliated with MI5, JTAC or the UK Government. For the official level, see mi5.gov.uk/threat-levels.
If you see something suspicious, report it at gov.uk/ACT. In an emergency, call 999.
Questions
What is the UK terrorism threat level today?
The UK national terrorism threat level is SEVERE, meaning an attack is highly likely. It was raised from substantial on 30 April 2026. The separate level for Northern Ireland-related terrorism in Northern Ireland is substantial.
What are the five UK threat levels?
From lowest to highest: low (an attack is highly unlikely), moderate (possible but not likely), substantial (likely), severe (highly likely) and critical (highly likely in the near future).
Who sets the UK threat level?
The Joint Terrorism Analysis Centre (JTAC), based at MI5, sets the national level independently of ministers. MI5 sets the level for Northern Ireland-related terrorism in Northern Ireland.
How often has the UK been at critical?
Four times since levels were first published in August 2006: August 2006 (airliner plot), June 2007 (Glasgow Airport), May 2017 (Manchester Arena) and September 2017 (Parsons Green). Each lasted two to four days.
What was the threat level before 2006?
Levels were assessed internally but not published before 1 August 2006. This site shows estimates back to 1968, based on the tempo of attacks and contemporary press reports. They are not official gradings.