The National Security and Investment Act 2021 (“NSI Act”) came fully into force on 4 January 2022, setting up a new regime for UK government scrutiny of acquisitions and investments. The NSI Act applies retrospectively to transactions from 12 November 2020.

The NSI Act is intended to modernise UK Government’s powers to investigate and intervene in investments, mergers and acquisitions and other deals to protect national security as a foreign-direct investment (FDI) regime, while applying to UK and non-UK acquirers alike. It replaces the national security element of the Enterprise Act 2002. The regime is a hybrid mandatory and voluntary notification regime, supported by call-in powers on national security grounds.