Approved Contractor Scheme

What it is

The Approved Contractor Scheme is the SIA's company-level approval scheme for the UK private security industry — the counterpart to the SIA's individual licensing. In the SIA's words it "is a quality assurance scheme for the private security industry" and "provides a recognised hallmark of quality within the private security industry". It is not a certificate: the Private Security Industry Act 2001 places a statutory duty on the SIA to "establish and maintain a register of approved providers of security industry services" (section 14), and the scheme's detail is set by the Private Security Industry Act 2001 (Approved Contractor Scheme) Regulations 2006 (SI 2006/425). Assessment is scored: "The contractor is scored against 78 achievement indicators."

Who owns it

The scheme is run by the Security Industry Authority (SIA), "an executive non-departmental public body, sponsored by the Home Office", which launched it in 2006.

Who asks for it

Buyer-driven. Participation is voluntary — approval is not a market-wide condition. The one structural driver evidenced is internal to the scheme: "Approved contractors may only sub-contract to other approved contractors unless we have given them special permission to do otherwise."

Participation is a choice, in the SIA's own words: "Participation in our ACS is voluntary, so any company that is part of the scheme has chosen to be." The SIA addresses its guidance to buyers of security services. One structural driver sits inside the scheme itself: "Approved contractors may only sub-contract to other approved contractors unless we have given them special permission to do otherwise" — so approval is a condition of working in an approved contractor's supply chain. Whether any UK public buyer requires ACS approval as a tender condition was not verified in the sources reviewed as of 29 August 2026 — confirm against the contracting authority.