How to Check if a Security Company Is SIA ACS Approved

To check if a company is SIA approved, search the SIA’s free online Register of Approved Contractors by the company’s name, then open its entry and confirm the legal name, the activities it is approved for and the expiry date of its approval. If the company is not on the register, it is not an SIA approved contractor, whatever its website or tender says.

This guide walks you through the register step by step, explains what each field means, and lists the red flags and supplier questions that procurement teams, facilities managers and councils should use. It also covers how security company owners should show their status correctly. For the bigger picture on the scheme itself, see our SIA ACS accreditation support page.

How to check if a company is SIA approved on the register

The SIA ACS register is a public search tool. You do not need an account, and it is free. It lists every organisation that currently meets the requirements of the Approved Contractor Scheme, so it is the only reliable SIA ACS checker. Lists on third-party sites can be out of date.

1. Open the register. Go to the Register of Approved Contractors on the SIA’s services site. GOV.UK’s guide to choosing an SIA approved contractor links to the same page.
2. Search by name. Type the company name into Search for contractor by name. Start with one distinctive word from the name (for example “Mitie” rather than the full group name), because the register matches the wording the SIA holds, not the brand you see on a van.
3. Or search by activity and region. Under Find Approved Contractors in Your Region, tick a licensable activity (such as Security Guard or Door Supervision) and pick a region. Ticking more than one activity shows only contractors approved for all of them, so tick one if you want a wider SIA approved contractor list.
4. Read the results table. Each result shows the Contractor, the Activities (sectors) approved as short codes, and the Expiry date of accreditation. The key above the table explains the codes: CVIT, CP, DS, KH, CCTV, SG and VI.
5. Open the full entry. Click the contractor’s name to see its detail page, then check each field against the supplier’s documents (see the table below).
6. Save evidence. Print the page to PDF or take a dated screenshot for your supplier file, and diary a re-check before the expiry date.

You can also use See All Approved Contractors to browse the complete SIA approved contractor register, which is useful when you are building a shortlist for a tender.

What does each field on the SIA approved contractor register mean?

The detail page tells you much more than the results table. Here is what each field means and what to check.

The register does not show a quality score. The SIA says most approved contractors are scored against 78 indicators each year, and you can ask for a contractor’s assessment report: the SIA can share it if the contractor gives permission.

Why do company names and legal entities cause confusion?

Most mistakes when checking ACS approved security companies come from names. A supplier may trade under a brand, sit inside a group, or have several limited companies with similar names. ACS approval belongs to the organisation named on the register, so you need to confirm that the company you are contracting with is that organisation (or is one of the companies a group entry lists).

A simple test: take the company name and number from the draft contract, look it up on Companies House, and check that it matches the SIA entry. For example, if a 40-officer guarding firm’s draft contract names one limited company but the register lists a differently named group company, ask which entity will employ the officers and hold the contract before you sign.

Red flags when checking a security company

• Not on the register. If you cannot find the company after searching by part of its name and browsing the full list, treat it as not approved. It is a criminal offence for a company to claim to be an approved contractor when it is not, including by displaying the ACS accreditation mark.
• Approval has lapsed or expires soon. An expiry date in the past, or one that falls before your contract starts, needs an explanation and evidence of renewal.
• Wrong legal entity. The approved company and the contracting company are different, with no clear link.
• Services not covered. You are buying door supervision, but the entry only shows Security Guarding. Approval is granted activity by activity.
• Undisclosed subcontracting. Approved contractors may only subcontract to other approved contractors unless the SIA gives permission, which is usually limited to exceptional cases and about three months. Ask who will actually deploy the officers.
• Additional conditions you were not told about. Conditions are not automatically a problem, but the supplier should be open about them.

What should you ask a security supplier?

Learning how to check if a company is SIA approved is the first step. These questions help you confirm that the approval covers the service you will actually receive.

• What is your ACS reference number, and which legal entity holds the approval?
• Which approved activities will you use on our contract?
• Will any of the work be subcontracted? If so, is the subcontractor an SIA approved contractor?
• Will you use labour from another company to supplement your staff? If so, who screens and vets those officers and checks their licences and right to work?
• For labour supply, is the provider certified to COP 119 or its replacement, BS 10119?
• How do you check that every officer holds a valid SIA licence for the role, and how often?
• Will you share your latest ACS assessment report, or allow the SIA to share it?

The SIA distinguishes subcontracting from use of labour. When a supplier uses labour from another company, it must make sure those operatives have been screened and vetted (or do its own checks), and it may be liable if unlicensed staff are found on site. That is why labour-provider certification matters. Our guide on how to get a COP 119 or BS 10119 certificate explains what labour providers are audited on.

For security company owners: how to show your ACS status correctly

Buyers will check you on the register, so make sure what they find matches what you say.

• Use your exact register name and ACS reference number in tenders, and say which entity holds the approval if you trade under a brand.
• List only the activities you are approved for. If you are approved for guarding but not door supervision, do not imply otherwise.
• Use the ACS accreditation mark only as the SIA allows. Follow the SIA’s guidance on the mark, and never put it on the website or paperwork of a group company that is not approved.
• Keep your entry current. Tell the SIA about significant changes, such as a change of business name, address or ownership.
• Do not let approval lapse. You must be assessed every year, submit an annual return and pay the annual registration fee of £25 for each licensable individual deployed, and renew every three years.

If you are not approved yet, our guide to getting SIA ACS approval covers eligibility, fees and timelines, and our walkthrough of the SIA ACS self-assessment workbook shows you how to complete the first big task. When your assessment is booked, use our SIA ACS assessment preparation guide.

Frequently asked questions

What does ACS approved mean?

It means the SIA has approved the company under its Approved Contractor Scheme for one or more licensable activities, after an independent assessment against the ACS standard (7 criteria, 33 sub-criteria and 78 indicators). Approval is pass or fail. There are no gold, silver or bronze levels.

Is ACS mandatory for security companies?

No. ACS is voluntary. However, many buyers and public contracts require it: for example, any contractor or subcontractor providing security services under a Scottish Government contract must be ACS approved.

What is the difference between an SIA licence and ACS?

An SIA licence is for individuals: the officer doing licensable work must hold one by law. ACS approval is for the business. An approved contractor still needs every officer to hold the right SIA licence.

How often are ACS companies reassessed?

Every year. An approved contractor must be assessed by an SIA-approved assessing body annually, re-register each year and renew its approval every three years. The SIA can add conditions or withdraw approval if a company falls below the standard.

Is there an SIA ACS list I can download?

The register’s See All Approved Contractors option shows the complete current list on screen. Always use the live register rather than an old download, because approvals change.

Can I check if a company is SIA approved by phone?

The online register is the quickest check, and it is what the SIA itself points buyers to. If something does not add up, ask the supplier for evidence first, then contact the SIA.

Sources: SIA Register of Approved Contractors; GOV.UK: Choosing an SIA approved contractor; GOV.UK: Learn about our Approved Contractor Scheme; GOV.UK: Keep your ACS approval; GOV.UK: Understanding ACS assessments; GOV.UK: Sub-contracting outside of the ACS; GOV.UK: Why apply for ACS approval. Last checked: October 2026.