Transactions & Deals in the United Kingdom

Full guide · Source-checked research100% of statements checked against a source145 checked against an official source0 checked against a secondary sourceChecked 2026-10-19Not yet professionally reviewed

• Acquisitions of more than 25%, more than 50% or 75% or more of the shares or votes in a qualifying entity active in one of 17 sensitive sectors must be notified to and approved by the government before completion under the National Security and Investment Act 2021.

  Mandatory sectors include advanced materials, artificial intelligence, communications, critical suppliers to government, data infrastructure, defence, energy, military and dual-use, quantum technologies and transport. Acquiring votes that allow passing or blocking any class of resolution is also a trigger.Cabinet Office · checked 2026-10-18

• A notifiable acquisition completed without approval under the National Security and Investment Act 2021 is void, and civil penalties can reach 5% of worldwide turnover or £10 million, whichever is greater.

  Criminal penalties also apply. Retrospective validation can be sought.Cabinet Office · checked 2026-10-18

• The government confirmed in March 2026 that it will revise the mandatory sectors (new water schedule, standalone critical minerals and semiconductors schedules, narrower AI and communications schedules) through secondary legislation, with no commencement date announced.

  Status at the check date; the current 17-sector regime applies until amending regulations are made.UK Parliament · checked 2026-10-18

• Acquisitions of certain entities active in 17 sensitive areas of the economy, including defence, energy and transport, must be notified to and approved by the government before completion under the National Security and Investment Act 2021.

  Applies regardless of the acquirer's nationality, including UK acquirers. There is no turnover threshold.Cabinet Office (Investment Security Unit) · checked 2026-10-18

• Mandatory notification is triggered by acquiring shares or votes that take a holding from 25% or less to more than 25%, from 50% or less to more than 50%, or from less than 75% to 75% or more, or voting rights that allow the acquirer to secure or prevent any class of resolution.

  Material influence and acquisitions of assets (land, tangible movable property, intellectual property) are not mandatory but can be notified voluntarily or called in.Cabinet Office (Investment Security Unit) · checked 2026-10-18

• A notifiable acquisition completed without approval is void.

  Civil and criminal penalties can also apply; civil penalties of up to 5% of worldwide turnover or £10 million, whichever is greater.Cabinet Office (Investment Security Unit) · checked 2026-10-18

• The government can call in a non-notified acquisition for assessment up to 5 years after it took place, and within 6 months of becoming aware of it.

  Applies to qualifying acquisitions that were not notified.Cabinet Office (Investment Security Unit) · checked 2026-10-18

• Once a notification is accepted the government has up to 30 working days to decide whether to call it in; a called-in deal faces a 30 working day assessment period that can be extended by a further 45 working days and further by agreement.

  Cabinet Office (Investment Security Unit) · checked 2026-10-18

Read the full guide: Entry, investment and company formation · Deals, investment screening and merger control