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ARTICLE · 11 DECEMBER 2025

The NSI Act

Katten
Katten
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The article examines the UK's National Security and Investment Act 2021, which grants the government the authority to review and intervene in acquisitions of control over UK entities and assets...

United KingdomTechnology
Edward A. Tran
Edward A. Tran
Oliver Williams
Oliver Williams
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The article examines the UK's National Security and Investment Act 2021, which grants the government the authority to review and intervene in acquisitions of control over UK entities and assets — regardless of deal value or investor nationality — particularly in sensitive sectors such as artificial intelligence (AI), defense, energy and data infrastructure. It outlines mandatory and voluntary notification triggers, review timelines, potential civil/criminal penalties (including void transactions and fines up to the higher of £10 million or 5 percent of global turnover), and the government's call-in, information-gathering and remedial powers. It emphasizes practical steps for accountants and deal teams, including integrating NSI screening into early due diligence, planning for timing, considering voluntary filings and maintaining accurate records.

"The NSI Act," International Accountant – The Professional Journal of the Association of International Accountants, November/December 2025

The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.

The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.

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