UK's highest classification for information whose compromise would cause exceptionally grave damage.
Top Secret is the UK's highest security classification, applied to information whose unauthorised disclosure would cause exceptionally grave damage to national security. Accessing Top Secret information requires DV clearance. Handling requirements are stringent—accredited high-security systems, controlled environments, and rigorous accountability. Top Secret work is limited to organisations with appropriate facilities and cleared personnel.
Why It Matters
The DSC Perspective:
Top Secret work requires substantial security investment and DV-cleared staff. Few organisations outside dedicated defence and intelligence sectors handle Top Secret. Requirements are significantly more demanding than lower classifications.