If you’ve been in the UK security industry for any length of time, you’ll have heard the term ACS. Many companies pursue it. Fewer achieve it first time. Fewer still understand precisely what assessors are looking for — and why the right technology can make a significant difference to how well prepared you are.
This guide explains the Approved Contractor Scheme in plain terms: what it is, why it matters, what assessors look for, and how operational technology supports the process.
What Is the Approved Contractor Scheme?
The SIA Approved Contractor Scheme (ACS) is a voluntary accreditation programme for private security companies operating in the United Kingdom. Companies that achieve ACS status have been assessed by an SIA-approved certification body against a structured set of professional and operational standards.
ACS is not legally required to operate a security company. But in practice, for companies seeking public-sector contracts, working in regulated environments, or competing against established firms in formal tender processes, ACS accreditation has become a de facto expectation. Many local authorities, NHS Trusts, universities, and large private-sector clients will not shortlist security suppliers that do not hold ACS approval.
What ACS Accreditation Signals
When a client sees the ACS mark on a security company’s materials, it communicates several things:
- The company is legitimately constituted and financially stable
- Guards hold the correct SIA licences, and those licences are monitored systematically
- Operational processes meet defined standards — incident reporting, supervision, communication, and documentation
- Staff receive ongoing training beyond the legal minimum
- The business has continuity plans and takes risk management seriously
For guards and supervisors, working for an ACS-approved company is also meaningful. It indicates that the employer is professionally run and that compliance is taken seriously rather than treated as box-ticking.
The ACS Assessment: What Assessors Look For
ACS assessments are scored against a structured question set that covers multiple areas of business and operations. Understanding these areas before you enter the process makes preparation significantly more straightforward.
Governance and Financial Stability
Assessors will examine your company structure, directorship, public liability and employers’ liability insurance, financial records, and evidence that the business is legitimately operated. This section catches companies that are technically operating but insufficiently formalised — whether that’s gaps in insurance, inadequate financial controls, or unclear ownership structures.
Management of SIA Licences
This is one of the most closely scrutinised areas of the assessment. Assessors want to see:
- A documented, repeatable process for checking guards’ licence status against the SIA Public Register
- Records demonstrating that those checks were actually carried out — not just a policy document saying you intend to carry them out
- A clear procedure for what happens when a licence lapses: who is notified, what redeployment or suspension process is followed, and how the outcome is recorded
Companies that check licences informally — or only at the point of hire — typically cannot produce the evidence this section requires.
Recruitment and Vetting
Beyond SIA licensing, assessors look at how you verify the identity and right to work of employees, and whether you conduct BS 7858 security screening — the industry standard for vetting security personnel that covers criminal records, employment history verification, and character references.
Assignment Instructions
Each client assignment should have a documented set of Assignment Instructions: a written record of what guards are expected to do at that site. This covers access control procedures, emergency and evacuation protocols, escalation contacts, reporting requirements, and any client-specific rules. Assessors will want to see that these documents exist, are current, and are communicated to the guards working those sites.
Many companies have informal assignment briefings that are perfectly adequate in practice but leave no audit trail. ACS requires the documentation, not just the practice.
Supervision and Performance Management
How do you know your guards are performing to the required standard? Assessors want evidence of a supervision framework: how often supervisors visit sites, how performance issues are raised and documented, and what happens when a guard consistently underperforms.
Incident and Complaint Management
Assessors will ask how your company logs, investigates, and responds to incidents and complaints. The ACS expects a formal, documented process — not informal resolution via phone calls that leave no record. What categories of incident do you track? How are they reviewed? What corrective actions are taken, and how are those actions recorded?
Health and Safety
Evidence of site-specific risk assessments, lone worker procedures, reporting processes for accidents and near-misses, and compliance with relevant health and safety legislation is required.
Why Companies Fail Their First ACS Assessment
The most common reasons for a first-time failure are worth understanding, because they’re preventable:
Insufficient documentation. Many security companies operate correctly in practice but cannot produce the paper trail that demonstrates it. Assessors can only credit what they can verify. Good operations that aren’t documented don’t score points.
Ad hoc licence monitoring. Checking licences informally, without a repeatable process or contemporaneous records, does not satisfy the ACS standard — even if every guard’s licence happens to be valid on the day of the assessment.
Outdated or missing Assignment Instructions. Instructions written at contract start and never reviewed since — or simply absent for some sites — are a common finding.
No formal incident log. Incidents managed via text messages or phone calls, with no structured record of what happened and what was done about it, leave an obvious gap.
How Technology Supports ACS Compliance
The right operational software does two things simultaneously: it makes your day-to-day operations more efficient, and it generates the compliance evidence that ACS assessors need to see.
Systematic Licence Monitoring
When guard licence status is tracked automatically against the SIA Public Register, you always have a current record of who is licensed and for which activities. A platform like TacDesk surfaces upcoming expiries before they become problems and maintains a timestamped history of licence status — precisely the kind of evidence an assessor looks for when reviewing your licence management processes.
Structured Incident Reporting
When guards submit incident reports through a structured digital form — with mandatory fields, timestamps, GPS location, and the ability to attach photographs — those reports automatically become a searchable, auditable trail. There’s no longer a question of whether an incident was logged, how it was classified, or what follow-up was taken.
Shift Records and GPS Clock-In Audit Trail
GPS-verified clock-in and clock-out records, combined with digital rota management, provide objective evidence that the right guard was on the right site at the right time. These records satisfy ACS requirements for shift documentation and support billing accuracy simultaneously.
Patrol Verification
If your guards conduct site patrols, digital patrol logging with checkpoint verification provides objective evidence of patrol completion. Assessors and clients alike value this kind of auditable record over a guard’s handwritten log in a site visitor book.
Is ACS Right for Your Company?
If you’re working with public-sector clients, competing on formal tender frameworks, or building a business that needs to grow sustainably, ACS accreditation is a worthwhile investment. The assessment is rigorous — by design, because the standard it sets is meaningful.
The good news is that most of what ACS assessors are looking for represents simply good practice: knowing who your guards are, confirming their licences are current, documenting what they’re expected to do on each site, and keeping records of what actually happens during a shift.
If your business already does these things — but informally — the primary work of ACS preparation is often documentation rather than operational change. The right technology makes that documentation a natural by-product of how you already operate, rather than a separate administrative burden.
To learn how TacDesk supports ACS compliance and SIA licence management for UK security companies, visit tacdesk.co.uk.