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Who we are
MI5 officers are ordinary people carrying out extraordinary work in secret
What we do
MI5’s mission is to keep the UK safe from threats
Where we are
MI5 officers work across the UK and overseas to support our mission
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Did You Know?

Espionage is another word for ‘spying’
Espionage is the word intelligence agencies use to describe spying. It involves getting secret information through human sources (agents) or technology, such as hacking into computer systems.
We can’t shout about our successes
We can’t shout about our successes
Due to the secret nature of their work, MI5 spies can’t talk about their achievements in public. However, they can celebrate successes with their colleagues, knowing that they are some of the only people in the country to know about a threat they helped prevent.
MI5 doesn’t just protect the country from terrorism
Although protecting against terrorism is our main focus, we also protect against foreign spies operating in the UK, work against cyber-attacks, and help protect some of the UK’s most sensitive sites, like nuclear power stations.
We’re all across the world
Although our mission is to protect against threats to the UK, that includes British people, companies and Embassies in other countries. Whilst MI6 take the lead overseas, we work with them to investigate threats and keep British interests safe.
We’re the oldest intelligence agency in the world...
MI5 has existed since 1909, making us (and MI6) the most experienced intelligence agencies around today. Back then, we were known as the ‘Secret Intelligence Bureau’, which then branched out to MI5 and MI6 in 1914.
...Even though we’ve only ‘officially' existed since 1992
MI5 was only 'officially' declared in 1992, 83 years after it was founded. Up until this time, not even the Director-General was named in public.

Latest News

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MI5 Director General and Head of CT Policing give joint interview for podcast

MI5 Director General Ken McCallum and head of Counter-Terrorism Policing Neil Basu gave their first joint interview for...

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MI5 joins Instagram

MI5 has joined Instagram with the aim of lifting the lid on what it's really like to work at the Security Service.

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