Imprisonment for Public Protection (IPP)

This note explains IPP sentences, which were introduced in England and Wales by the Criminal Justice Act 2003 and came into force in April 2005, before being abolished in December 2012.¹ The sentence proved controversial because it was imposed in a wider range of cases than Parliament had anticipated, and there was inadequate provision of offending behaviour courses for individuals who received an IPP sentence. This meant that many of them found it difficult to demonstrate to the Parole Board that they were safe to be released after they had served their minimum term. The abolition of the IPP sentence did not have retroactive effect, which means that a large number of individuals continue to serve an IPP sentence many years after the abolition of the sentence.

Why were IPP sentences introduced?

IPP sentences were introduced to enable sentencing courts to impose an indeterminate sentence on a person who was considered to be dangerous, but whose offence was not serious enough to meet the requirements for a life sentence. A person with an indeterminate sentence cannot be automatically released from prison at a certain future point in time; they must serve a minimum term and, once this minimum term has been served in full, they become eligible to apply to the Parole Board for release. Release will only be granted where the Parole Board is satisfied that the person no longer needs to be confined for the protection of the public.

A person serving an indeterminate sentence can, therefore, be kept in prison for the remainder of their life, should they not be able to satisfy the Parole Board that they are safe to release. If an IPP prisoner is released from prison, they are liable to remain on licence for the rest of their lives (meaning that they can be returned to prison if they breach their licence conditions or commit any further offences). IPP prisoners subject to life licence can apply to have their licence cancelled 10 years after they have been released from prison.

Changes effective from 1 February 2025 have cut the eligibility period for the Parole Board to consider ending licences from ten years after first release to three. IPP prisoners who have been released on licence at least five years ago and have not been recalled in the last two years will have their licence automatically terminated. This is the one substantive way in which the IPP sentence differs from a life sentence, as people with a life sentence can never have their life licence cancelled.

In what circumstances were IPP sentences imposed?

When the IPP sentence regime came into force in April 2005, it became apparent that these new indeterminate sentences were being imposed more frequently than the Government had anticipated – including for offences that were not in themselves particularly serious.

The IPP sentence was available to courts where a person had been convicted of one of 96 specified ‘serious’ violent or sexual offences (offences which carried a maximum sentence of 10 years or more) and where the court considered that the person posed a ‘significant risk of serious harm’ in the future. A particularly significant factor that led to the greater than anticipated imposition of IPP sentences was that any offender convicted of one of these 96 offences was presumed to pose a significant risk of serious harm if they had ever previously been convicted of either one of the 96 ‘serious’ offences or a further 57 ‘specified’ offences (for which the maximum sentence was between two and seven years).

Therefore, where an offender was convicted of one of the serious offences and they had a previous conviction from one of the 153 specified offences, the court had to consider the person to be dangerous and impose an IPP sentence, unless the court found it unreasonable to do so. This presumption of dangerousness was abolished by the Criminal Justice and Immigration Act 2008, which established that a minimum term had to be at least two years in order for an IPP to be available (there had not previously been a minimum length, and minimum terms could be as short as a few months).

What is the test to determine whether someone is a ‘dangerous’ offender?

Under the provisions of the Criminal Justice Act 2003, a person is dangerous if ‘the court is of the opinion that there is a significant risk to members of the public of serious harm occasioned by the commission by him of further specified offences’.² When making this assessment, the court must take into account all information available about the nature and circumstances of the offence, and may take into account any previous convictions, whether the offending amounts to a pattern of behaviour, and any other information about the person which is before them.

‘Significant risk’ has been interpreted by the courts to mean ‘a higher threshold than mere possibility of occurrence and in our view can be taken to mean (as in the Oxford Dictionary) ‘noteworthy, of considerable amount or importance’.³ ‘Serious harm’ is defined by the Criminal Justice Act 2003 as death or serious personal injury, whether physical or psychological.

Why did IPP sentences need to be amended?

The combination of the presumption that a person was dangerous if they had a previous conviction from the list of 153 specified offences (some of which had a maximum sentence of two years and were therefore not amongst the most serious of offences) with there being no minimum threshold for the length of sentence that should be imposed for the current offence, meant that IPP sentences were imposed on a wider pool of people than the Government had anticipated.

Some people who received an IPP sentence, and who could therefore potentially spend the rest of their lives in prison, had not committed particularly serious offences. By the end of June 2008, just over three years after the IPP sentence was introduced, the sentence had been imposed on almost 4,500 people. 34% of them had a minimum term of two years or less.⁴

A consequence of the greater than anticipated use of IPP sentences was that there was insufficient supply of rehabilitative programmes within the prison system, which meant that people who received an IPP sentence were not able to access courses that might reduce their risk factors and enable them to secure release by the Parole Board. This was a particular problem in the case of people serving short minimum terms, who often served their whole minimum term before they could access any courses – but their failure to complete these courses meant that they could not secure release by the Parole Board.

What changes did the Criminal Justice and Immigration Act 2008 introduce?

The amendment introduced in 2008 sought to address the two most significant problems concerning the IPP sentence: the presumption of dangerousness where an offender had a previous conviction for a specified offence (even if that offence had been unrelated, relatively minor and a long time ago), and the lack of a minimum term (which meant that an indeterminate sentence could be imposed for offences that were not particularly serious). The Criminal Justice and Immigration Act 2008 introduced a minimum term of two years (except in the rare cases where the offender had a previous conviction for one of 23 very serious offences) and removed the presumption in favour of dangerousness where an offender had a previous conviction for a specified offence. IPP sentences also became discretionary; where the conditions were met, an IPP sentence ‘may’ be imposed rather than, as previously, ‘must’ be imposed.

Did the reforms in 2008 alleviate the problems with IPP sentences?

The reforms in 2008 meant that IPP sentences became better targeted, as they were only available where a person had committed a relatively serious offence (one that merited them spending at least two years in prison) or, less commonly, where they had committed a less serious offence on this occasion but had previously been convicted of a more serious offence. As IPP sentences became discretionary, judges could reserve the imposition of indeterminate sentences for the most serious offenders. However, the reforms were not retroactive in effect, and did not alleviate the controversy surrounding the large number of people who remained in prison after the completion of a relatively short minimum term.

What replaced IPP sentences in 2012?

The IPP sentence was abolished by the Legal Aid, Sentencing and Punishment of Offenders Act 2012 and replaced by a new extended sentence (see our separate explainer on Extended Sentences) and an automatic life sentence for a person convicted of a second very serious violent or sexual offence (see our explainer on Life Sentences). These reforms applied to anyone convicted on or after 3 December 2012.

How many IPP sentences were imposed?

A total of 8,711 IPP sentences were imposed – more than 1,000 IPP sentences for every year the sentence was in existence.⁵ On 31 December 2024, there were 1,045 people in prison serving an IPP sentence who were yet to be released from prison for the first time (two-thirds of these people have been held for at least ten years beyond the end of their tariff). There were a further 1,569 people with an IPP sentence who had been released but subsequently recalled to prison.⁶

1. A similar sentence of Detention for Public Protection was also introduced for those aged under 18 or, in certain circumstances, for those aged between 18 and 21. ↩︎
2. A specified offence is any one of the 153 offences listed in Schedule 15 to the Criminal Justice Act 2003. ↩︎
3. Lang [2005] EWCA Crim 2864 at [17]. ↩︎
4. Jacobson, J. and Hough, M. (2010) Unjust Deserts: imprisonment for public protection. Prison Reform Trust, p. 12. ↩︎
5. HM Inspectorate of Prisons (2016) Unintended consequences: Finding a way forward for prisoners serving sentences of imprisonment for public protection, p. 10. ↩︎
6. Ministry of Justice (2025) Offender Management Statistics quarterly: July to September 2024, Prison Population: 31 December 2025. ↩︎