Monday 21 September 2020

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The National Security Inspectorate (NSI) is recognised as the leading certification body for the security and fire protection sectors in the UK. For over 40 years, we have helped protect businesses and homeowners by providing robust, high quality audits of home and business security and fire safety service providers. Businesses and homeowners who choose NSI approved companies have the reassurance that their chosen contractors will work to the highest industry standards demanded by the Police, Fire and Rescue Services and the insurance industry. The NSI Directory lists all the companies who have successfully achieved NSI certification.

A brief history

Security Systems

The NSI story began in 1971 with the formation of the National Supervisory Council for Intruder Alarms (NSCIA), to deal with the problem of poor quality installations and ‘cowboys’ within the intruder alarm market.

20 years later, the National Approval Council for Security Systems (NACOSS) was formed from the merger of NSCIA and the Security Systems Inspectorate (SSI). Its role was to continue to improve standards in line with increasingly tougher requirements of the insurance sector and the police national alarms policy.

NACOSS was instrumental in improving standards in the security industry, achieving widespread recognition from insurers, police and security buyers. CCTV and access control systems were added to the portfolio covered by NACOSS

Specialisms also include Scaffolding security systems.

Guarding Services

The Inspectorate of the Security Industry (ISI) – formed in 1992 –  offered a voluntary inspection regime for the security guard sector. In 2001, ISI and NACOSS merged to create a unified inspectorate – the NSI, covering all elements of the security industry, with the goal of creating one definitive certification body for the benefit of customers and suppliers.

In the Guarding Sector NSI continues to deliver independent audit across a wide spectrum of British Standards specific to the sector, and also since 2006, when first appointed, serves as an Assessing Body for the Security Industry Authority (SIA) Approved Contractors Scheme (ACS).

Facilities Management approvals – typically compliment guarding services approvals held by security companies, and NSI delivers an integrated package of approvals to these organisations.


In 2001, NSI extended its scope into the fire detection and alarm systems sector to include the BAFE SP203 scheme.  Many security companies already installed fire detection systems, so extending our skills to inspect companies who design, install, commission and maintain these systems was a logical step.  It also approves companies involved in the maintenance of portable fire extinguishers to the BAFE SP101 scheme –  Contract Maintenance of Fire Extinguishers.Emergency Lighting Schemes -SP203-4, followed as has Fire Risk Assessors – BAFE SP 205 Life Safety Fire Risk Assessment Scheme  in 2012, and the Kitchen Fire Protection Scheme BAFE SP 206 in 2019.