The Approved Contractor Scheme (ACS) is a voluntary scheme run by the Security Industry Authority (SIA). It recognises private security companies that meet independently assessed standards for service delivery, management, and staff training.
Although ACS registration is not a legal requirement, many buyers of security services — including government bodies, local authorities, and large private organisations — require their contractors to hold ACS status. Being listed on the SIA's register of approved contractors demonstrates that your company operates to a recognised standard.
1. Check your eligibility
Before applying, confirm your business meets the basic eligibility criteria:
- Your company must have been trading in the private security industry for at least 12 months
- All operatives carrying out licensable activities must hold valid SIA licences
- Your business must be able to demonstrate management systems for staff vetting, training, supervision, and complaints handling
- You must not have any unspent criminal convictions or enforcement actions from the SIA that would disqualify your application
If your company has been trading for less than 12 months, you cannot apply yet. Use the time to build compliant management systems and ensure all operatives are individually licensed.
2. Choose a UKAS-accredited assessment body
ACS assessment is carried out by independent bodies accredited by the United Kingdom Accreditation Service (UKAS). You must choose one of the following to conduct your assessment:
- British Assessment Bureau (BAB)
- National Security Inspectorate (NSI)
- Security Systems and Alarms Inspection Board (SSAIB)
Each body charges its own fees and has slightly different scheduling processes, but all assess against the same SIA-set criteria. Contact each one to request a quote based on your company size and the number of sectors you operate in.
3. Prepare for assessment
The assessment covers your business operations, management practices, and staff records. Before your assessment date, make sure you have the following in order:
- Staff licensing records — evidence that all operatives carrying out licensable activities hold valid SIA licences, and that you check licence validity regularly
- Recruitment and vetting procedures — documented processes for identity verification, right to work checks, and reference checks
- Training records — records of induction training, ongoing professional development, and any specialist training (such as conflict management or first aid)
- Supervision and management — evidence of how you supervise operatives, including site visit records and performance reviews
- Complaints and incident handling — a documented procedure for receiving, investigating, and resolving complaints
- Financial management — evidence that your business is financially stable (this may include accounts or financial references)
Your chosen assessment body will provide a self-assessment checklist. Complete this thoroughly before the formal assessment visit.
4. Complete the assessment
The assessment body will carry out an on-site visit (or visits, depending on company size) to verify your documentation and interview staff. The assessment typically covers:
- Review of management systems and documentation
- Interviews with directors, managers, and a sample of operatives
- Spot checks on SIA licence validity for named staff
- Review of client contracts and service delivery records
If the assessment body identifies areas that do not meet the required standard, you will be given an opportunity to address these before a final decision is made. Minor non-conformities can usually be resolved within a set timeframe without failing the assessment outright.
5. Maintain your approved status
Once approved, your company is listed on the SIA's public register of approved contractors. To maintain your status:
- Annual surveillance visits — your assessment body will conduct at least one follow-up visit per year to confirm continued compliance
- Reassessment — a full reassessment is required every three years to renew your ACS registration
- Notify changes — inform the SIA and your assessment body of any material changes to your business, such as change of directors, new operating sectors, or enforcement actions
- Ongoing licence checks — continue to verify that all operatives hold valid SIA licences throughout the year
If your company fails a surveillance visit or reassessment, your ACS status may be suspended or withdrawn. The SIA publishes removal decisions on its public register.
Once you have ACS status, prominently display the ACS logo on your marketing materials and tenders. Many procurement frameworks — including those used by NHS trusts, local authorities, and central government — require or favour ACS-registered contractors.
What next
- Check whether your operatives need individual SIA licence renewals — see Apply for an SIA licence
- Review your obligations under the Private Security Industry Act 2001 — see Legal requirements for private security businesses
- If you operate in multiple sectors (such as door supervision and CCTV), ensure each sector is covered in your ACS application