UK investment scrutiny intensifies: NSIA notifications and final orders reach record high

Below, we summarise the key numbers and take a deep dive into what they mean for businesses, investors and advisers – alongside a look at the proposed reforms published in parallel with the report.

Record notifications (and orders)…

The Government received 1,143 notifications during the reporting period, a 26% increase from the 906 notifications recorded in 2023-24. This includes:

• 954 mandatory notifications (up from 753).
• 134 voluntary notifications (up from 120).
• 55 retrospective validation applications (up from 33).

The number of call-in notices – arguably the clearest signal of active Government intervention – also rose sharply. 56 transactions were called in for further review, compared to 41 in the previous year. Notably, seven of these were non-notified transactions, indicating that the Government continues to monitor the market independently of formal notifications.

Of all reviewed transactions, 5.2% were called in, up slightly from 4.8% last year.

Perhaps most significant is the increase in final orders, which rose from 5 in 2023 – 24 to 17 in the current reporting period, including one order to unwind a transaction – the first of its kind under the NSIA.

This escalation in enforcement demonstrates growing confidence in using NSIA powers, and suggests a more interventionist stance where national security risks are identified.

…but what are the sectors most affected?...

Defence remained the most scrutinised sector, accounting for:

• 36% of call-ins.
• 9 of the 17 final orders issued.

Military and dual-use technologies followed closely, representing 29% of call-ins and 6 final orders.

Emerging and enabling technologies – particularly advanced materials and AI – are also under increasing scrutiny. AI was cited in 29% of final notifications, underlining its growing strategic relevance.

Geopolitical factors continue to inform decision-making. Of the transactions called in:

• 48% involved UK-associated acquirers.
• 32% involved acquirers associated with China.
• 20% involved US-linked acquirers.

… the calm after the storm

Alongside the annual report, the  Government has launched a public consultation on proposed amendments to the Notifiable Acquisition Regulations – the rules that define which sectors are subject to mandatory notification under the NSIA.

Published on 22 July 2025, the consultation reflects feedback from the Government’s earlier call for evidence (issued in November 2023) and forms part of the wider “Plan for Change” programme aimed at improving regulatory efficiency without compromising national security.

Key proposals include:

• Separating out two new standalone sectors:
  • Semiconductors (expanding and merging with the current Computing Hardware category).
  • Critical Minerals (currently within Advanced Materials).
• Refining the scope of 8 existing sectors, including Advanced Materials, AI, Communications, Data Infrastructure, and Energy.
• Adding “Water” as a new mandatory sector, covering companies with statutory water or sewerage duties (but excluding retail-only suppliers in the non-household market).

Separately, the Government also announced proposals to remove certain low-risk transactions from mandatory notification, including internal reorganisations within corporate groups, and the appointment of liquidators, special administrators, and official receivers. These reforms are intended to reduce compliance burdens in cases that rarely give rise to national security concerns.

The consultation is open until 14 October 2025.

For more on these proposals, see our analysis here: From safeguard to springboard: Reforms to the UK's National Security and Investment Act to boost economic dynamism | Fieldfisher

Key takeaways for businesses and investors

The latest figures show that the NSIA is becoming an increasingly central tool in the UK’s national security toolkit. For acquirers and their advisers, the implications are clear:

• Early engagement and risk assessment are essential, particularly in high-risk sectors.
• Geopolitical context matters – acquirer nationality continues to be a significant risk vector.
• Keep abreast of reforms, as changes to the sector definitions could alter notification obligations.

If you would like to discuss any of the issues covered in this blog, please contact Andrea Carrera or Asfand Gulzar.