Guidance

Offence of endangering another during a journey by sea (accessible)

Updated 19 December 2025

Version 1

About this guidance

This guidance tells you about the offence of endangering another during a journey by sea to the UK, introduced by the Border Security, Asylum and Immigration Act 2025.  This offence has been introduced to address acts that cause or risk the serious personal injury or death of another during small boat crossings to the UK, and in turn to reduce the risk of injury and fatality during these crossings.

Contacts

If you have any questions about the guidance and your line manager or other senior cannot help you, or you think that the guidance contains factual errors, then please email Migrant Criminality Policy Team.

If you notice any formatting errors in this guidance (broken links, spelling mistakes and so on) or have any comments about the layout or navigability of the guidance then you can email the Guidance, Rules and Forms team.

Publication

Below is information on when this version of the guidance was published:

• version 1.0
• published for Home Office staff on 15 December 2025

Background

The Border Security, Asylum and Immigration Act 2025 (the Act) introduced new measures to strengthen the system-wide response to border security threats. This includes to identify and disrupt organised immigration crime, which facilitates small boat crossings to the United Kingdom (UK).

The Act includes a new criminal offence of endangering another during a journey by sea to the UK from France, Belgium or the Netherlands. In this guidance, it will be referred to as the endangerment offence. This offence is introduced as a new criminal offence under section 24 of the Immigration Act 1971 (Illegal entry and similar offences) and provides the potential for increased sentencing (compared to certain existing immigration offences under section 24).

The endangerment offence is intended to equip law enforcement and prosecutors to address acts that cause, or risk, the serious personal injury or death of another, during a journey by sea to the UK. Further details of the application of the offence are set out in this guidance.

The Border Security, Asylum and Immigration Act 2025 introduced the endangerment offence by amending section 24 of the Immigration Act 1971. The offence was commenced on 5 January and applies to relevant offending committed on or after 5 January.

For guidance on the section 24 offence see: Criminal investigation guidance - Nationality & Borders Act 2022 amendments to the Immigration Act 1971

Overview of the offence

This section provides further details about the endangerment offence and sets out the factors that must be present for the offence to apply.

The endangerment offence is intended to target specific acts that create additional risk on an already dangerous journey by sea to the UK. It is intended to address acts that cause, or risk causing serious personal injury to or the death of another person.

For the offence to apply, all of the following elements must be present:

• the person must have committed an offence under subsection (A1), (B1), or (D1) (the offence also references (E1) under section 24; however, this offence has not yet been commenced) of section 24 of the Immigration Act 1971
• the person’s journey which resulted in their entry to or arrival in the UK must have been a journey by water from France, Belgium or the Netherlands
• at any time during that journey (between the point the individual left dry land in France, Belgium or the Netherlands and reaching dry land in the UK), the person committed an act that caused, or created a risk of, the death of or serious personal injury (physical or psychological) to another person

The offence was commenced on 5 January and applies to relevant offending on or after that date.

Factors to consider

When considering the use of the endangerment offence, you must take account of the following:

• the offence must be considered on a case-by-case basis with reference to the specific facts of the case and available evidence
• the offence is an additional tool to deal with the separate issue of acts that cause or pose a risk of death or serious personal injury during a journey by sea to the UK, alongside existing offences. It is not a replacement of section 24 or 25 offences
• it is not designed as a blanket offence for any person taking a dangerous journey to the UK. Public commitments have been made that boarding an unsafe vessel, or making a sea crossing, is not in itself intended to be in scope of the offence (though relevant endangering acts during the boarding phase would be in scope if they fulfil the necessary elements of the offence, provided they have left dry land)
• there is no exemption for the parent or parents of a child who are at risk of death or serious personal injury
• the offence is intended to capture any relevant endangering act, without giving a fixed list of what those acts are
• the offence does not directly affect or remove a person’s asylum claim
• the offence covers positive acts, not omissions or failure to act (further details in section 3 (Act that endangers another))

Territorial application

Extraterritorial application

The offence has extraterritorial jurisdiction meaning it will cover incidents during journeys by sea from France, Belgium, or the Netherlands to the UK.

This is most relevant to where the relevant act takes place. It is expected that in most cases the suspect would be apprehended or subsequently pursued by law enforcement within the UK, since for the offence to apply the person must have also entered or arrived in the UK committing an offence under section 24 Immigration Act 1971.

Wales, Scotland and Northern Ireland

The endangerment offence applies across the UK.

Committing a section 24 offence

This section tells you about an offence under section 24 of the Immigration Act 1971.

In order for the endangerment offence to apply, the person must have committed an offence under one of the following subsections of section 24 of the Immigration Act 1971. (The offence also references (E1) under section 24, however this offence has not yet been commenced):

• (A1) Knowingly entering the UK in breach of a deportation order
• (B1) Knowingly entering the UK without leave, where they require leave to enter the UK under the Immigration Act 1971
• (D1) Knowingly arriving in the UK without a valid entry clearance, where they require entry clearance under the immigration rules

The journey by sea during which the endangering act occurs must result in the commission of a relevant section 24 offence. This means that a prior section 24 offence (that is committed during a different journey on an earlier date) cannot be relied upon for application of the endangerment offence, for example if the small boat was intercepted before reaching the UK and returned to the country it departed, even if a relevant act of endangering another occurred.

Subsection D1 of section 24 Immigration Act 1971 provides for the offence of knowingly arriving in the UK without the entry clearance required by the Immigration Rules. This allows for the prosecution of a person who is intercepted in UK territorial seas and brought into the UK. The endangerment offence also applies to cases in which a boat is intercepted before reaching the UK, and is brought to the UK, where the other elements of the offence (journey by sea to the UK and endangering act) are met.

In line with usual practice, CPS will consider the appropriate charges based on the facts and evidence of the case.

Journey by sea to the UK

This section tells you what is meant by a journey by sea to the UK.

In order for the endangerment offence to apply, the person’s journey to the UK must have:

• been by sea
• started in France, Belgium or the Netherlands
• resulted in their entry or arrival in the UK and which constituted a section 24 offence

The relevant period of the journey, during which the endangering act must occur, is the period from when a person leaves dry land in France, Belgium or the Netherlands, until the person reaches dry land in the UK. This means that as soon as a person is in any level of water, including shallow waters, they are liable for the offence should they commit an act that endangers another person, provided the rest of the relevant factors were met. This includes the process of boarding in shallow waters and includes the first vessel if there are more than one in the journey (for example taxi to a further vessel).

It is expected that this journey would usually be in a small boat, but it is the journey by water that is specified, not the mode of transport nor number of boats used during a journey by sea.

Act that endangers another

This section tells you about the act of endangering another person.

In order for the endangerment offence to apply, the person must have done an act that caused, or created risk of, the death of or serious personal injury to another person.

There is no requirement to show that the person intended to cause, or create risk of, death or serious personal injury to another.

There must be a ‘positive’ act that can be identified and evidence, that is it must be something the person does, not the absence or omission of an act.

The Border Security, Asylum and Immigration Act defines personal injury as meaning physical or psychological injury. This means the outcome the act causes or risks could relate to both the physical and mental health of the individual. It is important to specifically consider the outcome caused or risked by the specific act itself (that is there needs to be a causal link between the endangering act and the resulting harm), not the wider situation.

Relevant period

The Border Security, Asylum and Immigration Act sets out the period during which the act must have occurred for the offence to apply. This can be at any time during the relevant period.

The relevant period begins when the person first left dry land in France, Belgium or the Netherlands for the purpose of making the journey.

The relevant period ends when the person first reached dry land in the UK.

Further details are set out in Journey by sea to the UK.

The relevant act can occur before the person commits the section 24 offence required under section 24 (E1A)(a), provided that offence subsequently occurs.

Person who is endangered

The Act does not specify who the other person (that is the person who is endangered) may be. This means it could be the endangerment of any other person, including others taking the journey; law enforcement; or those involved in rescue operations.

See below for examples.

Official - sensitive: start of section

The information on this page has been removed as it is restricted for internal Home Office use

Official - sensitive: end of section

Penalty

On conviction, the endangerment offence carries a maximum sentence of either:

• five years imprisonment or a fine (or both)
• six years imprisonment or a fine (or both), if the relevant section 24 offence is under subsection (A1) (knowingly enters the UK in breach of a deportation order)

If the endangerment offence is found not to apply or the individual is found not guilty of the endangerment offence, it does not preclude conviction of offences in (A1), (B1) or (D1) under section 24 Immigration Act 1971.

Prosecutor guidance is in place on the prosecution of immigration offences, including on evidence and Common Law and Statutory Defences, including duress.

A defence may be available under section 45 Modern Slavery Act 2015, where an person commits an offence as a result of compulsion attributable to their exploitation. It is important to note this defence and to be aware of risks of exploitation and modern slavery in the context of small boat crossings. Where the offence is committed as a result of modern slavery, the defence is under the Modern Slavery Act 2015; there is no separate defence under the endangerment offence as this is not required.