The Counter-Terrorism and Security Act 2015 establishes targeted travel and investigative powers: it authorises seizure and short-term retention of travel documents at ports on reasonable suspicion of involvement in terrorism, and creates Temporary Exclusion Orders (TEOs) preventing return to the UK unless a Secretary of State permit or deportation applies. TEOs require prior judicial permission in non‑urgent cases and post‑imposition review; breaches and failure to comply with imposed obligations are criminalised, with specified sentencing limits and bespoke procedural safeguards including special advocates and closed material provisions.

The Act also updates TPIMs (residence, travel, weapons and appointments), extends retention of internet identifiers, introduces authority‑to‑carry schemes and enhanced passenger/crew data obligations, and strengthens aviation, maritime and rail security with civil penalties. It imposes a statutory duty on listed public bodies to have due regard to preventing people being drawn into terrorism, mandates local multi‑agency panels for assessment and support, and provides oversight via statutory reviews, appeal routes and a Privacy and Civil Liberties Board.