MI5 - Security Service

MI5 The Security Service

Report a threat

To report an imminent threat call 999 or ring the Anti-Terrorist Hotline on 0800 789 321

To report non-urgent suspicions:
Contact Us here


Current UK threat level


Read more about threat levels >>

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The Security Service (MI5) is responsible for protecting the United Kingdom against threats to national security. This website provides information about the Security Service, the threats it counters, links to sources of security advice and details of careers with the Service.

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MI5 today and our challenges tomorrow

17 September 2015

The Director General appeared on Radio 4 to speak about MI5 and security challenges ahead....