The UK’s national terrorism threat level is currently:
SUBSTANTIAL - An attack is likely.The threat level is designed to show the likelihood of an attack happening, but it doesn’t mean an attack is expected in a specific place or at a specific time.
The five threat levels
The UK’s system has five levels to show the likelihood of a terrorist attack in the UK:
- Low – an attack is highly unlikely
- Moderate – an attack is possible, but not likely
- Substantial – an attack is likely
- Severe – an attack is highly likely
- Critical – an attack is highly likely in the near future
The level provides guidance for the government, police and security partners to respond.
For example, Substantial sits in the middle of the scale, giving a reminder to remain alert, but not a reason for alarm. At the Critical level, additional security measures and public alerts may be introduced until the threat reduces.
How is the level decided?
This UK terrorism threat level is set by security experts at the Joint Terrorism Analysis Centre (JTAC) and the Security Service (MI5). They review available information including intelligence about terrorist intent, capability, intentions and timing.
It’s important to remember:
- The system measures likelihood, not certainty – it doesn’t predict where or when an attack might happen.
- The threat level can change quickly if new information emerges.
- There’s no fixed review schedule – updates to the threat level happen whenever intelligence suggests a shift in risk.
Why the threat level changes
The threat level moves up or down depending on a range of factors, such as:
- The emergence of credible plots or specific intelligence
- Developments in global or domestic terrorism
- Arrests or disruptions that reduce capability
- Wider events, such as conflicts or political changes, that may influence threat intent
A raised level doesn’t always mean there’s an immediate danger to the public. It means security and emergency services are adjusting their readiness to keep the country safe.
What the threat level means for businesses and the public
While the national threat level mainly guides government and police responses, it’s also useful for businesses and the public.
At any level, everyone has a part to play in keeping people safe:
- Stay alert and report anything suspicious to police or via the ACT (Action Counters Terrorism) website.
- Review your security measures – access control, video surveillance, emergency plans and staff awareness.
- Encourage staff vigilance, especially in crowded or public-facing environments.
- Avoid alarm, but stay informed through trusted official sources.
For organisations, these small steps help reduce risk and improve preparedness. At Cobac Security, we help businesses across the UK maintain strong, proportionate security – ensuring teams and premises remain safe, compliant and confident at every threat level.
Learn more
You can find out more about the latest threat levels and official advice here:
