About NSI approved companies

About NSI approved companies

About NSI approved companies

About NSI approved companies

Experts in Security and Fire Safety

NSI approval is a highly respected and trusted hallmark in the security and fire sectors, demonstrating technical expertise and a reassuring quality of service. 

More than 2000 companies hold approval for one or more of a wide range of services including intruder alarm and CCTV system installations, mobile / static guards and key-holding, life safety fire risk assessment, fire alarm and fire suppression systems. 

The vast majority of NSI approved companies choose to hold Gold approval which includes in all cases ISO 9001 approval for Quality Management Systems. 

NSI approved companies are all subject to a rigorous audit programme annually. They may be required to make improvements e.g. in their operations or competency, or have their approval withdrawn, subject to auditor findings.

NSI is the UK’s premier UKAS accredited independent certification body within the security systems, guarding services and fire safety sectors. 

Buyers and specifiers are reassured their NSI approved security and fire safety providers are reputable and trustworthy with the expertise to translate needs into dedicated solutions.

Many insurers recognise NSI approved companies and the systems they install. Check with your insurer whether having a system installed and maintained by an NSI approved company enables you to receive a discount on your insurance premium. 


Search the NSI Company Finder or ask your NSI approved company for sight of their unique Certificate of Approval for the specific services for which they are approved by NSI.

Buyers choosing an NSI approved company can have confidence they:

Undergo a rigorous application process before approval is granted

Open their business to independent, regular audit by our highly trained team of industry specialist auditors

Ensure their business and management are of good repute

Have accepted the obligation to put in place corrective actions raised during an NSI audit

Issue an NSI Certificate of Compliance for security and fire safety systems as evidence they are installed to relevant standards

Observe and comply with NSI regulations at all times

Provide ongoing appropriate training for their staff ensuring the required level of skill

Have suitable insurance and business premises

Have a robust financial standing

Work to International and British Standards and NSI Codes of Practice, teams have relevant technical experience

Operate a Quality Management System to ISO 9001 combined with unique NSI Quality Schedule (Gold approved companies)

Have reputable Directors & leaders with relevant business experience and effective employee security screening

Look out for the NSI hallmarks


NSI Gold companies meet the industry’s highest technical standards and maintain a commitment to continual improvement with scrutiny of their ISO 9001 Quality Management System. 


NSI Silver companies meet the industry's technical standards which are listed on their Certificate of Approval. 


Learn more about NSI

About us

Our Schemes

NSI in the Media 2023



Governance and Impartiality

Meet our team

Find an NSI approved company