MI5's mission is to keep the country safe
For more than a century we have worked to protect the UK from a range of national security threats.
Find out what we do
Careers at MI5
Explore the wide range of career opportunities at MI5
Security advice
The National Protective Security Authority (NPSA) is part of MI5 and offers advice to businesses and organisations to help keep them and their customers safe from a range of national security threats.