OFFICIAL-SENSITIVE

OFFICIAL-SENSITIVE is a handling marking used within the UK Government Security Classifications policy. It is not a separate classification tier: it identifies a subset of information at the OFFICIAL level that requires additional care in handling because compromise, loss or inappropriate sharing could cause more serious damage than for ordinary OFFICIAL information. The policy is periodically revised, so the authoritative wording is always the current Cabinet Office Government Security Classifications policy itself.

The UK classification scheme has three tiers — OFFICIAL, SECRET and TOP SECRET — with OFFICIAL covering the majority of routine public-sector information. The SENSITIVE caveat flags that a document, though at OFFICIAL, warrants tighter need-to-know controls and more careful handling, and it is often accompanied by descriptors indicating the nature of the sensitivity. The permitted descriptors and marking conventions are set out in the official government guidance, which should be treated as the definitive reference.

For AI deployment the marking matters because it signals information that should not be processed on systems, or sent to services, that are not approved to handle it. Working with OFFICIAL-SENSITIVE material typically points towards deployment inside a controlled environment — on-premises, in an approved in-region private environment, or air-gapped — rather than a public AI service, so that the handling requirements attached to the information are met by the system processing it. Specific accreditation and approval requirements should always be confirmed with the relevant authority for the system in question.