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 the Security Service via the How You Can Help us page.

See threat level history for previous changes.

See The UK’s threat level system for more information on what threat levels mean, who decides the level of threat and how the threat level system is used.

Current Threat Level

The current threat level from international terrorism for the UK is assessed as – SEVERE

The threat level for Northern Ireland-related terrorism is set separately for Northern Ireland and Great Britain. In Northern Ireland it is SEVERE and in Great Britain SUBSTANTIAL.

SEVERE ~ means that a terrorist attack is highly likely

SUBSTANTIAL ~ that an attack is a strong possibility

CRITICAL ~ means an attack is expected imminently

The Government continues to maintain a state of heightened readiness in response to the threat from international terrorism. It remains the Government’s policy to issue warnings or advice if this ever became necessary to protect public safety in the event of a specific and credible terrorist threat.

Source and form of the Threat

The threat of international terrorism comes from a diverse range of sources, including Al Qaida and associated networks, and those who share Al Qaida’s ideology but do not have direct contact with them. A threat could manifest itself from a lone individual or group, rather than a larger network.

Domestic terrorism related to Northern Ireland, principally from Republican terrorist groups, also remains a threat.

The terrorist threat can take a number of forms, as terrorists may use a variety of methods of attack to achieve their objectives. These may include explosive devices, firearms, missiles, kidnapping, infiltration and electronic attacks.

See the Centre for the Protection of National Infrastructure (CPNI) website for practical advice on how to defend against these threats.

This page has been produced in consultation with the Joint Terrorism Analysis Centre (JTAC). It will be regularly reviewed and updated. Whilst every care has been taken in preparing this summary, the Security Service accepts no liability for any statement contained therein (see our Content Disclaimer).