UK Security Glossary

SIA Approved Contractor Scheme

The SIA Approved Contractor Scheme is the Security Industry Authority's voluntary quality benchmark for UK security companies. To qualify, a provider has to demonstrate documented operational management, vetted staff, financial sustainability and customer-service standards through an independent annual assessment. Around 800 UK security companies hold ACS — a small fraction of the total market. ACS is not a per-officer licence; it sits above the SIA Security Officer / Door Supervisor licences that individual staff hold, and is the closest thing the UK has to a quality kitemark for the company itself rather than its people.

Security Industry Authority Licence

Every individual UK security officer working in licensable activities (manned guarding, door supervision, close protection, CCTV operation, key holding, vehicle immobilising) must hold a current SIA licence. There are six licence types — a Security Officer working a static guarding role on a construction site needs a different licence to a Door Supervisor at a venue. Licences are issued for three years, are revoked for criminal convictions, and are individually verifiable on the public SIA Register. The licence is on the person, not the company.

National Security Inspectorate Gold

NSI Gold is the highest accreditation level offered by the National Security Inspectorate, the UK's leading certification body for the security and fire industries. Gold-rated providers are independently audited annually against three layered standards — the relevant technical standard (e.g. BS 8243 for confirmed alarms), ISO 9001 quality management, and the NSI's own Gold scheme requirements. NSI also operates Bronze and Silver tiers, which audit fewer dimensions. NSI Gold is most commonly seen on companies that install monitored alarms, monitored CCTV, fire detection systems, and Alarm Receiving Centres.

Security Systems and Alarms Inspection Board

SSAIB is the second of the two major UK certification bodies for the security and fire industries (the other being NSI). Like NSI, SSAIB runs a layered scheme — full members are audited annually against the relevant technical standards (BS EN 50131 for intruder alarms, BS 5839 for fire, BS 5979 / Cat II for ARCs), plus operational and customer service criteria. SSAIB certification is widely accepted by UK insurers and police forces as equivalent to NSI for purposes of confirmed-alarm response and insurance compliance.

Contractors Health and Safety Assessment Scheme

CHAS is one of the UK's leading pre-qualification schemes for contractor health and safety. Holding a current CHAS Premium / Premium Plus / Elite assessment means the company's H&S management has been audited against SSIP (Safety Schemes in Procurement) Core Criteria — risk assessments, training records, accident reporting, RAMS workflows, and director-level H&S accountability. CHAS is widely recognised by Tier 1 construction firms and public-sector buyers as a baseline pre-qualification, often saving the buyer the work of running their own bespoke H&S vetting.

Constructionline Gold

Constructionline is the UK's largest pre-qualification platform for construction-industry suppliers. Bronze, Silver and Gold are progressive certification tiers — Gold members complete the SSIP H&S assessment plus financial, environmental, equality, and policy checks, all renewed annually. Most major UK construction clients (Tier 1 contractors, local authorities, public-sector buyers) require Constructionline membership at minimum Silver to enter their supply chain. Gold often replaces individual buyer pre-qualification questionnaires entirely.

SafeContractor (Alcumus SafeContractor)

SafeContractor is one of the UK's most widely-used contractor pre-qualification schemes. Operated by Alcumus, it's an annual desktop assessment of a company's health and safety, environmental, and operational management systems. SafeContractor accreditation is recognised by 350+ buying organisations (housing associations, retail chains, FM companies, local authorities) and frequently appears alongside or instead of CHAS / Constructionline in their supplier lists.

Safety Management Advisory Services Worksafe

SMAS Worksafe is another SSIP-recognised pre-qualification scheme for UK contractors, focused on health and safety management. Like CHAS and SafeContractor, it audits the company's H&S documentation, accident records, training and management responsibility — and once you hold one SSIP-aligned certificate, the data is reusable across the others to save duplication.

BS 7858 — Security screening of individuals employed in a security environment

BS 7858 is the British Standard for vetting individuals employed in security roles — guards, ARC operators, CCTV monitors, key holders. It specifies the minimum checks that must be carried out before someone takes up a security-sensitive role: identity, employment history (typically 5 years), education, criminal record, financial probity, and right-to-work. The current edition is BS 7858:2019. Most ACS-approved companies vet to BS 7858 as standard.

BS EN 50131 — Alarm systems for buildings

BS EN 50131 is the European / British Standard for intruder and hold-up alarm systems. It defines four security grades — Grade 1 (low risk, domestic), Grade 2 (commercial / domestic with valuables), Grade 3 (high-value commercial), Grade 4 (high-value targets, vaults). Insurers usually specify a grade based on the premises' risk profile. The standard covers system design, components, signalling, monitoring and maintenance — not just the alarm panel.

ISO 9001 — Quality Management Systems

ISO 9001 is the international standard for quality management systems. A certified organisation has documented processes for handling customer requirements, complaints, continuous improvement, internal audit and management review — assessed externally each year. In the UK security industry, ISO 9001 sits alongside (and is partly required by) NSI Gold and SSAIB Gold. Many providers carry ISO 9001 directly even when they don't hold NSI / SSAIB.

National Association of Security Dog Users

NASDU is the UK trade body for security dog handler units, setting accreditation levels (1-3) for handler skill and dog certification. Level 2 is the practical operating standard for working security dog handlers — combining handler training, dog behavioural assessment, scent / search / patrol work, and ongoing competence reviews. NASDU also runs accreditation for dog handling instructors (Level 3) and for kennel facilities. Most insurance and procurement teams require Level 2 minimum for any security dog deployed on a UK site.

BS 5839 — Fire detection and alarm systems

BS 5839 is the British Standard for the design, install, commissioning and maintenance of fire detection and alarm systems in non-domestic premises. Part 1 covers commercial buildings (offices, retail, hospitality, industrial), Part 6 covers houses in multiple occupation (HMOs) and dwellings. The standard prescribes detection categories (L1-L5 for life safety, P1-P2 for property protection, M for manual-only) — your fire risk assessor specifies the right category based on the building's use, occupants, and fire risk.