What ACS is
The Approved Contractor Scheme is the SIA's voluntary quality mark for security suppliers. It assesses the business, not the individual officer.
How it is assessed
Assessors score against 87 indicators across strategy, resources, delivery and results. A minimum score is required to pass; higher scores signal better operators.
The candidate view
Working for an ACS-approved contractor typically means predictable pay, training investment and a route to progression. Unapproved operators are not automatically bad, but the median experience is worse.
The client view
Buying from an ACS-approved contractor gives you a baseline of assurance on staff vetting, training and supervision. Score matters — a bare-pass supplier is not the same as a top-quartile one.
Getting or renewing ACS status
Applications take 3–6 months. Annual re-audit. Non-conformances must be closed within tight windows or approval is withdrawn.