Emergency: call 999
If there is immediate danger or urgent police assistance is needed, call 999. In an attack, contact police when it is safe to do so and follow their instructions.
Official information and practical guidance
UK Terrorism Threat Levels
Understand the five threat levels, find the latest official assessment and know where to report a concern. This USSG guide directs you to MI5 and Counter Terrorism Policing information.
Go to the official source
What is the current UK threat level?
Check the MI5 threat levels page for the latest published assessment. This page is a reference guide, not a live alert service, and does not automatically monitor changes.
The UK-wide terrorism assessment covers England, Scotland, Wales and Northern Ireland. MI5 also publishes a separate assessment for Northern Ireland-related terrorism in Northern Ireland. Check the scope of the assessment you are reading.
Understanding the scale
What do the five terrorism threat levels mean?
The scale describes the assessed likelihood of a terrorist attack. These are terrorism threat levels, not weather warnings or a general natural-disaster scale.
Low
The assessed likelihood of an attack is very low.
Moderate
An attack could occur, but is not considered likely.
Substantial
An attack is considered likely.
Severe
The likelihood of an attack is assessed as high.
Critical
The likelihood is high and an attack could occur in the near future.
Plain-language summaries above. Read the official MI5 definitions → for the source wording.
Use the right reporting route
How to report a terrorism concern
Non-emergency terrorism concerns
Report a concern through the official ACT reporting route or call the Anti-Terrorist Hotline on 0800 789 321. The police can assess the information you provide.
Use official police channels for reports. USSG’s commercial enquiries are not an alternative to emergency services or the police reporting process.
Public safety guidance
Run, Hide, Tell
Counter Terrorism Policing provides Run, Hide, Tell guidance for firearms and weapons attacks. In brief:
- Run: escape if there is a safe route. Leave belongings behind.
- Hide: if escape is unsafe, find cover and silence your phone, including vibration.
- Tell: call 999 when safe and follow police instructions.
For site and business managers
Review the arrangements for your premises
Use official guidance alongside your organisation’s risk assessment. Practical discussion points for your site team include:
- Who receives official updates and briefs the team.
- How staff report concerns and contact emergency services.
- Access arrangements for visitors, deliveries and contractors.
- Emergency procedures, staff awareness and clear responsibilities.
Visit ProtectUK and the National Protective Security Authority for official protective security resources.
Questions about threat levels
Does USSG publish live terrorism alerts?
No. This page provides guidance and links to official sources. Check MI5 for the latest published threat assessment.
Does the national threat level predict an attack at my site?
No. It provides national context and does not replace an assessment of the risks and security arrangements at an individual site.
Which number should I call in an emergency?
Call 999 for immediate danger or urgent police assistance. For non-emergency terrorism concerns, use the official ACT reporting route or the Anti-Terrorist Hotline on 0800 789 321.
Does the UK-wide assessment include Wales?
Yes. The UK-wide assessment includes England, Scotland, Wales and Northern Ireland. A separate assessment is also published for Northern Ireland-related terrorism in Northern Ireland.
Official sources reviewed: 5 October 2026. This is the review date of this guide, not a live threat-level update. Sources: MI5 and ProtectUK. External resources open in a new tab.