Threat Levels

What are Threat Levels?

Members of the public should always remain alert to the danger of terrorism and report any suspicious activity to the police on 999 or the anti-terrorist hotline: 0800 789 321. If your information does not relate to an imminent threat, you can also contact MI5.

Current national threat level

The threat to the UK (England, Wales, Scotland and Northern Ireland) from terrorism is SUBSTANTIAL.

Current Northern Ireland Related Terrorism in Northern Ireland threat level

The threat to Northern Ireland from Northern Ireland-related terrorism is SEVERE.

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What the threat levels mean

Threat levels are designed to give a broad indication of the likelihood of a terrorist attack.

  • LOW means an attack is highly unlikely
  • MODERATE means an attack is possible, but not likely
  • SUBSTANTIAL means an attack is likely
  • SEVERE means an attack is highly likely
  • CRITICAL means an attack is highly likely in the near future

How are threat levels decided?

The threat level for the UK from international terrorism is set by the Joint Terrorism Analysis Centre (JTAC).

MI5 is responsible for setting the threat level from Northern Irish Related Terrorism in Northern Ireland.

In reaching a judgement on the appropriate threat level in any given circumstance several factors need to be taken into account.

These include:

  • Available intelligence. It is rare that specific threat information is available and can be relied upon. More often, judgements about the threat will be based on a wide range of information, which is often fragmentary, including the level and nature of current terrorist activity, comparison with events in other countries and previous attacks. Intelligence is only ever likely to reveal part of the picture.
  • Terrorist capability. An examination of what is known about the capabilities of the terrorists in question and the method they may use based on previous attacks or from intelligence. This would also analyse the potential scale of the attack.
  • Terrorist intentions. Using intelligence and publicly available information to examine the overall aims of the terrorists and the ways they may achieve them including what sort of targets they would consider attacking.
  • Timescale. The threat level expresses the likelihood of an attack in the near term. We know from past incidents that some attacks take years to plan, while others are put together more quickly. In the absence of specific intelligence, a judgement will need to be made about how close an attack might be to fruition. Threat levels do not have any set expiry date, but are regularly subject to review in order to ensure that they remain current.

How should you respond?

Threat levels in themselves do not require specific responses from the public. They are a tool for security practitioners working across different sectors of the Critical National Infrastructure (CNI) and the police to use in determining what protective security response may be required.

Vigilance is vital regardless of the current national threat level. It is especially important given the current national threat. Sharing national threat levels with the general public keeps everyone informed. It explains the context for the various security measures (for example airport security or bag searches) which we may encounter in our daily lives.

If you have information about possible terrorist activity, call the Anti-Terrorist Hotline: 0800 789 321.

The Anti-Terrorist Hotline is for tip-offs and confidential information. For warnings about possible bombs or other urgent threats please call 999.

Threat level history

Since 2006, information about the national threat level has been available on the MI5 and Home Office websites. MI5 took on responsibility for National Security work in Northern Ireland in 2007 and is responsible for setting the threat level for Northern Irish Related Terrorism. In September 2010 the threat levels for Northern Ireland-related terrorism were also made available.

In July 2019 changes were made to the terrorism threat level system, to reflect the threat posed by all forms of terrorism, irrespective of ideology. JTAC analyses and assesses all information relating to international terrorism at home and overseas. It is responsible for setting the threat level for Great Britain (including Islamist Terrorism, and the Right and Left Wing Terrorism in Northern Ireland).


National Threat Level

Date Threat Level
9 February 2022 SUBSTANTIAL
15 November 2021 SEVERE
4 February 2021 SUBSTANTIAL
3 November 2020 SEVERE
4 November 2019 SUBSTANTIAL
23 July 2019 SEVERE


Northern Irish Related Terrorism in Northern Ireland Threat Level

Date Threat Level
28 March 2023 SEVERE
22 March 2022 SUBSTANTIAL
23 July 2019 SEVERE


Threat levels prior to July 2019


Threat from international terrorism

Threat from Northern Ireland-related terrorism

in Northern Ireland

in Great Britain

1 March 2018

17 September 2017 SEVERE SEVERE


15 September 2017


27 May 2017


23 May 2017




11 May 2016




29 August 2014




24 October 2012




11 July 2011




24 September 2010


(first published)

(first published)

22 January 2010




20 July 2009




4 July 2007




30 June 2007




13 August 2006




10 August 2006




1 August 2006

(first published)



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