Collection

National Security and Investment Act 2021

Guidance and information about the National Security and Investment Act.

Ministerial Foreword

The UK is one of the most attractive destinations in the world for investors. To maintain that position, we need to ensure our economy remains as secure as possible while giving businesses the confidence and consistency to thrive.

The NSI Act is a vital part of that process. Introduced in 2021, it represents a major upgrade of the UK’s investment screening powers. It allows us to identify and manage risks to our national security - but in a sensible and proportionate way that allows investment to continue to flow.

The vast majority of businesses won’t have to engage with this regime. But for those that do, I want the process to be as light-touch and easy to navigate as possible. In February, I was made decision-maker under the NSI Act - and as we enter its second year, I intend to be even more open and transparent with businesses about the way this legislation works.

And so this second edition of market guidance provides important new information about how I use certain powers under the Act, including the power to make interim orders. It also provides details about how parties can interact with the system most effectively, for example through seeking voluntary periods where relevant, as well as additional information on timings - including when in an NSI assessment parties should expect to hear from the Investment Security Unit.

The first year of this legislation demonstrated the government’s ability to clear most cases within a prompt, business-friendly 30 working days, with no further action needed. This updated guidance builds on the experience of that first year, allowing this process to be as predictable as possible.

That way, businesses can continue to invest and grow with confidence - putting the UK as a whole in a position to flourish.

The Rt Hon Oliver Dowden CBE MP, Deputy Prime Minister and Chancellor of the Duchy of Lancaster. $CTA

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

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

A wide variety of parties invest in the UK economy, including private enterprises, institutional investors, sovereign wealth funds, state-owned enterprises, and individuals. The test for whether an acquisition is a qualifying acquisition, and whether it requires mandatory notification, relies on the facts of that acquisition and whether it meets the relevant tests of the NSI Act, rather than the characteristics or nature of the acquirer.

The ISU has been asked whether there are any plans to exempt certain businesses and investors. The NSI Act gives the government power to create exemptions from mandatory notification requirements based on the “characteristics” of the acquirer. There are currently no exemptions for any specific type of acquirers made under this power.

The government is monitoring closely how the NSI Act works in practice, analysing trends and risks to determine whether it would be appropriate to make exemptions to the mandatory notification requirements.

Any regulations which define exemptions to the mandatory notification system under the NSI Act would be subject to Parliamentary scrutiny.

Published 11 November 2020
Last updated 18 February 2024 + show all updates
  1. Updated to remove a notice on maintenance work due to it being completed

  2. Added a note that the NSI notification service will be unavailable for much of the day on Saturday 17th of February 2024 while essential maintenance takes place.

  3. Removed notification of maintenance as it has completed

  4. Added a notice regarding planned maintenance of the NSI notification service

  5. Updated the collection: Review of the operation of the NSI Act processes

  6. Updated to remove the notice of the call for evidence as it has now closed.

  7. Updated to remove the notice for maintenance as it has now been completed.

  8. Added a note that the NSI notification service will be unavailable for much of the day on Saturday 18th of November 2023 while essential maintenance takes place.

  9. Added a link to the page: Call for Evidence - National Security and Investment Act

  10. Adding a message to say that the NSI notification service will be unavailable for much of the day on Saturday 28th October 2023 while essential maintenance takes place.

  11. Updated to reflect the maintenance work was completed and the service is available again.

  12. Added a notice that the NSI notification service will be unavailable for much of the day on Saturday 23rd of September 2023 while essential maintenance takes place. We apologise for any inconvenience.

  13. Added a link to the following page: National Security and Investment Act 2021: Annual Report 2023

  14. Removed an update regarding maintenance on the system as it has been completed.

  15. Added a message to inform users that the NSI notification service will be unavailable for much of the day on Saturday 8th and Sunday 9th of July 2023 while essential maintenance takes place. We apologise for any inconvenience.

  16. Made text changes to accommodate the lates version of the National Security and Investment: Market Guidance April 2023

  17. Added a new section: Information gathering

  18. The NSI notification service will be unavailable for much of the day on Monday 10 April 2023 while essential maintenance takes place.

  19. Added link to Memorandum of Understanding concerning Parliamentary scrutiny of the work of the Investment Security Unit (ISU).

  20. The NSI notification service will be unavailable on Saturday 4 March 2023 while essential maintenance takes place.

  21. NSI notification service back online.

  22. The NSI notification service will be unavailable on the weekend of 14-15 January 2023 while essential maintenance takes place. We apologise for any inconvenience.

  23. Added link to Notice of Final Orders made under the National Security and Investment Act 2021.

  24. Added guidance for new build downstream gas and electricity assets.

  25. Added NSIA annual report 2022, and a Memorandum of understanding on the operation of the National Security and Investment Act 2021.

  26. Added National Security and Investment Act 2021: guidance on compliance and enforcement.

  27. The NSI notification service will be unavailable from 4:00pm Sunday 20 March to 9:00am Monday 21 March 2022, due to routine maintenance work. If you have any notifications in progress they will not be affected.

  28. The National Security and Investment notification service will not be available on Saturday 15 January 2022 between 8:00am and 9:00am while we undertake maintenance. If you have a notification in progress it won't be affected.

  29. The National Security and Investment (NSI) Act came into force on 4 January 2022. The new rules have now started and the National Security and Investment notification service is open.

  30. Added NSI notification service forms to provide details of the information that will be required when you submit a notification. The service goes live on 4 January 2022.

  31. First published.