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.
Issued by
Security Industry Authority (SIA), the UK regulator for the private security industry.
Why it matters
ACS status is the single best signal that a security company runs a tight operation — vetting, training, complaints handling and contract management are independently audited every year. Most insurance-mandated procurement specifies ACS. Without it, your buyer's due diligence is much harder.
Questions to ask a provider
- What's your current ACS score (out of 174) and when was your last audit?
- Which sections did you score highest / lowest on?
- Do you handle complaints in-house or via the SIA's process?
Related terms
Looking for a UK security provider with this accreditation? SitePatrol lists vetted providers across the UK — filter by accreditation, county and service.