Two changes pull screening in opposite directions
The Cabinet Office announced in March 2026 that it intended to refine mandatory screening under the National Security and Investment Act. The proposals would remove certain off-the-shelf AI activities from mandatory notification while bringing investments in the water sector into scope. This is a proposed regulatory change, not evidence that every described amendment is already in force.
The contrast reveals the policy objective. Screening should concentrate on control over sensitive capabilities and critical infrastructure rather than impose identical filing burdens on every transaction involving a fashionable technology label.
AI capability is not the same as AI distribution
A company selling general-purpose software may present a different national-security exposure from a business controlling specialist models, defence-relevant systems or sensitive data. Removing routine activities from a mandatory category could reduce unnecessary notifications, but deal counsel would still need to assess the precise legal definitions.
Mandatory notification and the government's power to call in other transactions are separate concepts. Falling outside a mandatory category does not necessarily mean a transaction is immune from scrutiny.
Water infrastructure raises a different continuity question
Water operators provide essential services with limited short-term substitutes. Changes of control can therefore affect operational resilience, information security and the ability to maintain services during emergencies. These are not equivalent to concerns about ordinary software licensing.
Investors should distinguish ownership of an operating utility from a minority holding in an unrelated technology supplier. The screening analysis depends on the target's activities, control rights and the regulations in force at the transaction date.
The cost of uncertainty can be measured in transaction time
A filing obligation affects transaction timetables, financing conditions and completion risk. For a hypothetical acquisition requiring three additional months before completion, carrying £100 million of acquisition finance at an annual 6% simple interest rate would cost approximately £1.5 million over that period. This illustration is not a government estimate or a prediction for any particular deal.
Clarity can therefore have an economic value even when no transaction is ultimately blocked. Conversely, under-screening strategically important assets could shift costs onto customers and taxpayers if continuity is compromised.
What advisers should verify before signing
The critical documents are the final statutory definitions, commencement dates, transaction structure and control thresholds. The government's March announcement is a policy statement, not a substitute for the operative regulations and updated guidance.
The durable takeaway is that national-security screening is becoming more discriminating. The commercial benefit depends on whether the eventual rules separate routine technology investment from genuinely sensitive control without creating new grey areas.