Skip to main content
Collection

National Security and Investment Act 2021

Guidance and information about the National Security and Investment Act.

The government has now published its response to the consultation on the NSI Act Notifiable Acquisition Regulations (NARs). This consultation response summarises the feedback received and sets out the changes that the government will take forward for each schedule of the NARs.

The National Security and Investment Act (NSI) came into force on 4 January 2022.

The NSI Act gives the government powers to scrutinise and intervene in business transactions, such as takeovers, to protect national security, while providing businesses and investors with the certainty and transparency they need to do business in the UK.

This page provides links to guidance on the rules and the accompanying legislation.

Submitting a notification about an acquisition

We have provided guidance on the information you need to complete a notification form.

We have also published the forms here so you can collect all the information you need before submitting your answers via the NSI notification service.

In exercising its statutory functions under the National Security and Investment Act 2021, the Investment Security Unit within the Cabinet Office may observe, monitor, record, retain and share within government internet data which is available to anyone. This is known as ‘open source’ material and includes:

  • News reports
  • Internet sites
  • Public records such as Companies House and Land Registry
  • Blogs and social networking sites where no privacy settings have been applied

The Cabinet Office may also use third party service providers, including aggregators of open-source information, to obtain information.

Submit a notification about an acquisition via the NSI service

Once accepted, all notifications are reviewed within 30 days, in line with statutory requirements. The time between submitting your notification to the ISU and your notification being accepted may vary based on demand and other factors in your notification.

Statement on the use of the call-in power

The Section 3 Statement sets out how the Secretary of State can exercise the power to give a call-in notice, as set out in section 3 of the NSI Act.

Principal guidance on the rules about acquisitions that could harm the UK's national security

  • NSI Act guidance overview: this guidance sets out what types of acquisitions are covered, when you need to tell the government about an acquisition, and how the government will scrutinise the acquisition
  • Guidance on notifiable acquisitions in the 17 mandatory areas: If an entity you are acquiring performs a certain activity, it could put you in scope of the National Security and Investment Act and you may be legally required to tell the government about it (known as a ‘mandatory notification’). This guidance tells you what these activities are.
  • How to submit a notification form: assists parties when completing a notification form and explains the information parties might need to include when completing the form. This is accompanied by a privacy notice explaining how the ISU processes personal data and how it applies data protection principles.
  • This flowchart is to help you decide whether you need to notify the government about an acquisition
  • Market Guidance notes: we will publish regular updates to the market on various aspects of the NSI Act.

Notice of final orders made under the Act

Annual reports

Legislation

Read the National Security and Investment Act 2021 on legislation.gov.uk.

Secondary legislation

Review of the operation of the NSI Act processes

The government is monitoring closely how the NSI Act works in practice, analysing trends and risks to ensure the system remains effective, efficient, and up to date.