How Prison Sentences Work

Prison sentences in England and Wales are not one simple “serve half” rule. Fixed (determinate) sentences, extended determinate sentences, and indeterminate sentences each work differently, and automatic release points for many standard determinate sentences have changed more than once. This guide is general orientation for families and the public — not legal advice, and not a personal release-date calculator.

United States federal and state sentencing systems are separate. Do not mix England and Wales release rules with a US result.

Official victim-facing explanation of current release-arrangement changes is on GOV.UK’s Progression model: changes to prison release arrangements. For offence-level sentencing guidance, see the Sentencing Council. Find an establishment in the Prison Finder.

Determinate sentences (including SDS)

A determinate sentence has a fixed length set by the court. Part is served in custody; the rest is normally served in the community on licence, with conditions and a risk of recall if those conditions are broken.

A standard determinate sentence (SDS) is the most common fixed sentence. How much of an SDS is served in custody before automatic release is set by legislation and can depend on the offence, when the sentence was imposed, and which release rules are in force. Recent years have seen temporary and then longer-term changes to those points (including measures often discussed as SDS40, and the Progression Model under the Sentencing Act 2026). Treat any “halfway” or “two-thirds” figure you read online as historical unless it matches the current official rule for that case.

After release on licence, contact with probation and restrictions can feel as important as the time inside. For day-to-day custody before release, see life inside prison. Reception and the first days are covered in what happens when someone goes to prison.

Extended determinate sentences (EDS)

Extended determinate sentences are used for certain serious violent or sexual offences where the court decides an extended period of supervision is needed after custody. They combine a custodial term with an extended licence. Release from the custodial term is not the same as SDS automatic release: parole consideration and the length of the custodial term matter. EDS cases are among the sentence types GOV.UK lists as outside the Progression Model’s SDS release changes.

Indeterminate sentences and life

Life sentences and other indeterminate sentences have no fixed “end date” in the way an SDS does. The court sets a minimum tariff that must be served before the Parole Board can consider release. If released, people on life licence can be recalled for the rest of their life if risk cannot be managed in the community.

Imprisonment for Public Protection (IPP) was abolished for new sentences in 2012, but people already serving IPP remain under that indeterminate framework until the Parole Board is satisfied they can be safely released. Exact numbers in custody change over time — use official MoJ statistics rather than informal totals.

Licence, recall, HDC, and ROTL

Licence conditions can include where someone must live, who they must not contact, reporting to probation, and other restrictions. Breach can lead to recall to custody. Home Detention Curfew (electronic tagging before the automatic release point) and Release on Temporary Licence (ROTL) are separate schemes with their own eligibility rules; neither applies to every prisoner or every offence.

Remand and categorisation

Time spent in custody on remand before sentence is normally credited against the sentence. Security category (and later moves between prisons) is a separate process from the sentence type itself.

See prison categories explained for Category A–D definitions, and use the Prison Finder for a named establishment.

US sentencing (high level only)

US jail, state DOC, and federal BOP sentences follow different statutes, guidelines, and good-time rules. Use the facility’s official pages and this site’s profiles rather than England and Wales release percentages.

Start from the Prison Finder if you need the correct US or UK facility page.