UK Threat Levels

The UK Threat Levels are the alert states that have been in use since 1 August 2006 by the British government to warn of forms of terrorist activity. Before then a colour-based alert scheme known as BIKINI state was used. The response indicates how government departments and agencies and their staffs should react to each threat level.

The current threat level is Severe, which was upgraded from Substantial on 29 August 2014.

Since 24 September 2010, the Home Office has reported three different categories of terrorist threat:

The Joint Terrorism Analysis Centre (JTAC) is responsible for setting the threat level from international terrorism and the Security Service (MI5) is responsible for setting both threat levels related to Northern Ireland. The threat level informs decisions on protective security measures taken by public bodies, the police and the transport sector.

Threat levels were originally produced by MI5's Counter-Terrorism Analysis Centre for internal use within the British government. Assessments known as Security Service Threat Reports or Security Service Reports were issued to assess the level of threat to British interests in a given country or region. They had six levels: Imminent, High, Significant, Moderate, Low and Negligible. Following terrorist attacks in Indonesia in 2002, the system was criticised by the Intelligence and Security Committee of Parliament (ISC) as insufficiently clear and needing to be of greater use to "customer departments".

The 7 July 2005 London bombings prompted the government to update the threat level system following a recommendation from the ISC that it should deliver "a greater transparency of the threat level and alert systems as a whole, and in particular [it is recommended] that more thought is given to what is put in the public domain about the level of threat and required level of alert." The system was accordingly simplified and made easier to understand. Since 2006, MI5 and the Home Office have have published international terrorism threat levels for the entire UK on their websites, and since 2010 they have also published threat levels for Northern Ireland, with separate threat levels for Northern Ireland and the rest of the UK.

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