About us

About us

About us

About us

Protecting UK homeowners and businesses for over 50 years

The National Security Inspectorate is the UK's most highly trusted and respected, independent, UKAS-accredited certification body in the security and fire safety sectors. 

As a not-for-profit organisation helping to protect homeowners, businesses, the public sector and the general public, we count premium local providers, as well as the UK's premier national security and fire safety providers amongst our clients. 

Our mission is to secure the highest standards of safety and security for buyers of commercial and domestic fire and security systems, guarding and security services, through independent, third party audit and certification in the UK and Eire.


Independently approved companies you can trust

Each year our expert, in-house team of auditors conduct over 3700 assessments of 2000+ NSI approved companies to verify compliance with relevant British and International Standards and industry Codes of Practice.

NSI approved companies are committed to the highest standards of service, quality and continual improvement.

By choosing to contract an NSI approved company, you can be assured of their integrity, technical expertise and professionalism as recognised by the Police, Fire and Rescue Services and the insurance industry.

NSI Gold and Silver logos

Look out for the NSI hallmarks

An NSI Certificate of Approval demonstrates an organisation operates in accordance with recognised industry standards for the services as listed in the NSI Company Finder.

Every NSI approved company operates a Quality Management System or business operating system and its board of directors has been screened. It also operates in accordance with NSI Regulations for Approved Companies, as well as relevant standards, through an ongoing programme of independent audits. 

Technically Competent

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


Gold approval - operating a Quality Management System to ISO 9001 and NSI Quality Schedules


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

NSI UKAS Accreditations

NSI is accredited by the United Kingdom Accreditation Service (UKAS)

UKAS accredits bodies such as NSI who operate certification schemes in accordance with International Standards for Accredited Certification i.e. ISO/IEC 17021-1:2015 (management systems certification) and ISO/IEC 17065:2012 (product conformity certification).

Insight Certification Ltd trading as National Security Inspectorate (NSI) is accredited by the United Kingdom Accreditation Service (UKAS), which operates under a Memorandum of Understanding with the UK Government through the Department for Business, Energy and Industrial Strategy.


Key milestones in our history


National Supervisory Council for Intruder Alarms (NSCIA) launched. Rear Admiral Desmond Callaghan CB appointed as Director General.


NSCIA becomes NACOSS (National Approval Council for Security Systems) launched from the merger of the NSCIA and SSI (Security Systems Inspectorate) under the leadership of Michael Vann, Chief Executive. The owl depicted in the NACOSS logo lives on today in our Gold and Silver medals.

The NACOSS Quality Assurance scheme was launched.


The Inspectorate of the Security Industry (ISI) was formed offering third party certification for the guarding services sector.

NACOSS receives NACCB accreditation (predecessor of UKAS) to deliver BS 5750 Quality Assurance certification, the pre-cursor to ISO 9001.


NACOSS becomes independent from guarantor the Loss Prevention Council under Chief Executive Dr David Holt.


NSI became a founding stakeholder of the national apprentice skills competition - 'Engineers of Tomorrow'.


National Security Inspectorate (NSI) was formed from the merger of NACOSS (National Approval Council for Security Systems) and ISI (Inspectorate of the Security Industry).


NSI is the first certification body licensed by BAFE to provide third party certification for providers of fire detection and alarm systems.


The Royal Mint is commissioned to produce our coveted Gold and Silver medals for display by NSI approved companies under NSI's Chief Executive, Tom Mullarkey MBE, incorporating the owl depicted in our NACOSS logo.


NSI appointed as one of the first Security Industry Authority's (SIA) Assessing Bodies for the launch of the Approved Contractor Scheme (ACS) under Tom Mullarkey, NSI Chief Executive. Shortly afterwards, NSI became the first SIA Assessing Body permitted to offer the ACS Passport Route.


A new certification division for security companies is launched in the Republic of Ireland - CerticCS.


NSI granted UKAS accreditation to deliver BAFE's Life Safety Fire Risk Assessment Scheme SP205.


NSI granted UKAS accreditation to deliver BAFE's Emergency Lighting Scheme SP203-4.


The Surveillance Camera Commissioner launches the new Surveillance Camera Code of Practice certification scheme for operators of public space surveillance systems. NSI is appointed as a third party certification body for the scheme.

NSI gains UKAS accreditation for 102000 - Provision of Investigative Services and ISO 9001:2015, the latest edition of the Quality Management standard


The number of NSI approved companies in the UK reaches 1800.

The first organisation gains certification for the Surveillance Commissioner's Surveillance Camera Code of Practice through NSI.


NSI launches the BAFE Kitchen Fire Protection Systems Scheme SP206.

NSI celebrates 20 years of independence from the Loss Prevention Council.


NSI granted UKAS accreditation to deliver BAFE's Kitchen Fire Protection Systems Scheme SP206.

UKAS accreditation also granted for Occupational Health & Safety certification to ISO 45001.


NSI publishes new NSI Code of Practice NCP 119 – Provision of Labour in the Security and Events Sectors.


NSI celebrates 50 years of delivering certification and raising standards in the security sector - safeguarding people, property and the wider community.

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