SIA Approved Contractor Scheme

SIA Approved Contractor Scheme

SIA Approved Contractor Scheme

SIA Approved Contractor Scheme

For further information or to apply

If you are interested in becoming an SIA Approved Contractor please complete our online Enquiry Form

If you have any questions, please contact our sales team who will be happy to help.

T: 01628 764885

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Security guard verification checks at live event

SIA Approved Contractor Scheme overview

Designed by the Security Industry Authority (SIA) in consultation with representatives from across industry, including NSI, the main objective of the Approved Contractor Scheme (ACS) is to raise performance standards in the Security Services sector by creating a framework for regulated businesses to develop and promote best practice. SIA ACS is not a compliance standard, it is non-prescriptive and can be applied by any organisation, regardless of size.

NSI has been an appointed Assessing Body for the SIA's Approved Contractor Scheme since its launch in 2006.


SIA ACS approval is a source of confidence for buyers of security services. Its framework for setting, improving and monitoring operating standards is increasingly becoming the minimum requirement for any company deploying a security service. SIA ACS approval is voluntary and instantly positions your company as having been independently assessed and meeting a recognised level of performance.

ACS covers those parts of the industry regulated by the SIA and the Private Security Industry Act 2001 (as amended), requiring the SIA to establish a "system of inspection for providers of security services, under which those organisations who satisfactorily meet the agreed standards may be registered as approved, and may advertise themselves as such".

Being an SIA Approved Contractor demonstrates your company is committed to customer service and provides reassurance your private security operatives deliver a quality service in any of the following areas in which you choose to be assessed:

  • Security Guarding
  • Keyholding
  • Door Supervision
  • Cash/Valuables in Transit
  • Public Space Surveillance (CCTV)
  • Vehicle Immobilisation (Northern Ireland)
  • Close Protection

How do I get ACS Approval?

Two routes to ACS Approval: Standard route & NSI ACS Passport Route

Standard Route

The Standard Route is open to any security company - previous certification is not required. It entails an in-house self-assessment which is then verified during an assessment visit by a qualified assessor from NSI.

How do I apply for the Standard Route?

Step 1 - To arrange an informal call with an NSI assessor to discuss your application and assessment process please contact one of our advisors by phone to arrange this on Tel: 01628 764885. (There is no charge for this).  

Step 2 – Visit the SIA website to find out details of the SIA's pre-eligibility checks and application process. You will be required to download the following documents to assist your ACS application:

Step 3 – Download, complete and submit the SIA’s Self Assessment Workbook:

Step 4 – Apply to the SIA for ACS approval

Step 5 - Once you have received your letter of acceptance from the SIA, contact NSI to make arrangements for us to come and conduct your verification assessment.  If you haven't already done so, call us now for a quotation. (N.B. Assessment fees will be payable prior to the visit taking place).

NSI ACS Passport Route

Already NSI approved? Or wishing to apply for Guarding or Cash Services? If ‘yes’, then you may be eligible for the ‘Passport’ route to ACS approval. 

This means NSI can combine your NSI audit with your ACS assessment, saving you time and money. 

Find out more about the NSI Passport Route.

Advantages of being an approved contractor:
  • Inclusion in the Register of Approved Contractors published on the SIA website.
  • Authority to use the ACS Accreditation Mark on stationery, livery and websites.
  • Approval may provide access to tender opportunities where ACS is a pre-requisite.
Why choose NSI as your assessing body?

For nearly 50 years NSI has provided industry specific certification, raising standards in the interests of the customer and was one of the first organisations to be appointed by the SIA as an ACS Assessing Body. The NSI auditing team are industry specialists whose knowledge and experience is second to none.


By choosing NSI, you will benefit in a number of ways:

Our straightforward friendly approach

Highly competitive, inclusive and transparent fees

You'll be assigned one of our specialist ACS assessors who'll provide impartial feedback on your ACS performance

A significant number of NSI assessed Passport and Standard route ACS companies achieve placement in the top 15% of all SIA ACS accredited companies

Straightforward transfer service

Companies with NSI Guarding or Cash Services approval can save on ACS approval via the 'Passport' Route

Build a relationship with the UK's most widely respected specialist certification body in the Guarding Services sector

Do I need a consultant?

Whatever the size of your organisation, the short answer is ‘maybe’. We are often asked this question by companies who are considering applying for the ACS Scheme.

Our experience is that many companies find expert industry guidance from our assessors is sufficient to assist you in becoming ACS approved. Contact us for more details.

T: 01628 764885

Already have SIA ACS approval?

Transferring your ACS assessment to NSI is easy...

An increasing number of companies are choosing to transfer their ACS assessment to NSI, to benefit from industry expert guidance. This is a straightforward process and we would be happy to provide you with further information and a personal quotation. Email or call us today to discuss your ACS transfer:

Contact our Applications team who will be happy to discuss your requirements, provide you with a competitive quote and guide you through the transition.


To apply for NSI approval, please complete our online Enquiry Form

View all NSI approval schemes