LegislationGB

National Security Act 2023

UK law covering Conduct that assists a foreign intelligence service.

The National Security Act received Royal Assent on 11 July 2023 and brought its foreign-intelligence-service offence into force on 20 December that year.

Last refreshed: 22 October 2026

Timeline for National Security Act 2023

#182 20 Oct

RAF tankers to fuel Saudi raids in Yemen

Iran Conflict 2026

View full timeline →

Background

The National Security Act 2023 is a United Kingdom law covering espionage, sabotage, foreign interference and the protection of sensitive sites. It received Royal Assent on 11 July 2023 and replaced or updated older national-security offences. The Act also created the legal basis for a foreign influence registration scheme.

Section 3 makes it an offence to materially assist a foreign intelligence service with UK-related activities intentionally, or when a person knows or ought reasonably to know the likely effect. Assistance can include information, goods, services or financial benefits. The offence applies to Conduct in the UK and some Conduct abroad, with defences for specified legal, public and governmental activity. It came into force on 20 December 2023 and carries a maximum sentence of 14 years.

Common Questions

Reference

What is the penalty for assisting a foreign intelligence service?

A section 3 conviction on indictment can bring up to 14 years' imprisonment, a fine, or both.Source: https://www.legislation.gov.uk/ukpga/2023/32/section/3

What does section 3 of the National Security Act 2023 prohibit?

Section 3 covers Conduct intended to materially assist a foreign intelligence service, and Conduct likely to do so where the person knows or ought reasonably to know that effect.Source: https://www.legislation.gov.uk/ukpga/2023/32/section/3

What does the National Security Act 2023 cover?

It addresses national-security threats including espionage, sabotage and foreign interference, and provides for registration of specified foreign arrangements and activities.Source: https://www.legislation.gov.uk/ukpga/2023/32/data.html

When did section 3 of the National Security Act 2023 take effect?

Section 3 came into force on 20 December 2023.Source: https://www.legislation.gov.uk/ukpga/2023/32/section/3

When did the National Security Act 2023 become law?

The Act received Royal Assent on 11 July 2023.Source: https://www.legislation.gov.uk/ukpga/2023/32/data.html

Source Material

National Security Act 2023 National Security Act 2023, section 3 National Security Act 2023

Written with AI from Lowdown's published reporting. Not individually reviewed by an editor. Updated 22 October 2026. Editorial standards.