PACE
Clock
Understanding the Legal Time Limits on Police Detention Under the Police and Criminal Evidence Act 1984 (2026)
Statutory Definition
What Is the
PACE Clock?
The PACE Clock is the legal time limit framework that governs how long police can detain a suspect without charge after arrest.
Under the Police and Criminal Evidence Act 1984, a suspect may normally be detained for up to 24 hours before they must either be charged with an offence or released from custody.
In certain circumstances this initial limit can be extended. Serious indictable offences may allow detention of up to 36 hours with authorisation from a superintendent rank officer, and up to 96 hours from the relevant time with warrants granted by a magistrates' court.
24 hrs
Standard Limit
Section 41 PACE
36 hrs
Superintendent Extension
Indictable offences only
96 hrs
Magistrates Maximum
Warrant of Further Detention
One of the most important safeguards within UK criminal procedure is the limit placed on how long police can detain a suspect without charge.
These limits are governed by the Police and Criminal Evidence Act 1984 (PACE) and are commonly referred to as the PACE Clock.
While many people assume police can hold suspects indefinitely while investigating offences, the reality is very different. Strict time limits apply, and those limits are closely monitored by custody officers, inspectors, and the courts.
Understanding how the PACE Clock works is essential for police officers managing custody suites, legal professionals advising clients, and members of the public who want to understand their rights after arrest.
Chapter 1
Why the PACE Clock Exists
Before the Police and Criminal Evidence Act came into force in 1984, the legal framework governing police detention was fragmented and inconsistent. Different powers applied in different circumstances, and there was no single coherent system of safeguards governing how long suspects could be held before they were either charged or released.
This legislative gap created serious risks. Suspects could be detained for extended periods while investigators conducted enquiries at their own pace. Without mandatory time limits or review obligations, the risk of abuse — whether deliberate or through administrative inattention — was significant.
The Problem PACE Solved
- → Suspects detained for days without charge
- → No mandatory review of detention necessity
- → No independent judicial oversight of extended detention
- → Inconsistent treatment across different forces
- → No obligation to release when grounds lapsed
What PACE Introduced
- → Strict 24 hour initial detention limit
- → Mandatory periodic reviews of detention necessity
- → Superintendent authorisation required for extensions
- → Independent judicial oversight via magistrates' court
- → Absolute 96 hour maximum without charge
The PACE Clock is therefore not simply an administrative tool. It is a fundamental constitutional safeguard. It reflects the principle, enshrined in Article 5 of the European Convention on Human Rights, that deprivation of liberty requires specific legal justification and cannot be indefinitely prolonged without independent oversight.
The detention clock applies pressure to investigators. Once a suspect is in custody the clock is running, and every hour of investigation counts. This creates a discipline that encourages efficient, focused investigation rather than indefinite exploratory detention.
Chapter 2
When the PACE Clock Starts
The PACE Clock begins at what the legislation calls the "relevant time". Understanding exactly when the relevant time occurs is critical, because all detention periods, review obligations, and extension authorities run from that moment.
Arrested and taken directly to one police station
The relevant time is when the detainee arrives at that police station. The clock starts the moment they are brought through the station doors.
Arrested and taken initially to another location before a police station
The relevant time is 24 hours after arrest, or the time of arrival at the police station — whichever is earlier. This prevents investigators from delaying custody booking to extend effective investigation time.
Arrested outside England and Wales and brought in
The relevant time is the time of arrival at the first police station in England or Wales to which the detained person is taken.
The custody officer is responsible for recording the relevant time on the custody record immediately on the detainee's arrival. This record is the master document governing the entire period of detention. All time calculations, review schedules, and extension applications are computed from the time entered on the custody record.
Practical Note for Officers
Accurate recording of the relevant time is not merely administrative formality. If the relevant time is recorded incorrectly, all subsequent detention periods, reviews, and extension authorities may be calculated from a false baseline. A detention review conducted late, or an extension applied for after the time has expired, may render the entire period of detention unlawful — with consequences for evidence admissibility under Section 78 PACE.
Chapter 3
The Initial 24-Hour Detention Period
Section 41 of the Police and Criminal Evidence Act 1984 provides that a person shall not be kept in police detention for more than 24 hours without being charged. This is the bedrock of the PACE custody framework and applies to all offences, from minor summary matters to the most serious indictable crimes.
Section 41 PACE 1984
"Subject to the following provisions of this section and to sections 42 and 43 below, a person shall not be kept in police detention for more than 24 hours without being charged."
During the initial 24-hour period investigators can conduct all standard custody procedures, including:
Booking into custody and biometric collection
Interviewing under caution (PACE Code E)
Searching the detainee under Section 54 PACE
Searching premises under Section 18 PACE
Seizing and examining property
Arranging forensic analysis
Consulting prosecutors on charge decision
Conducting ID procedures
Obtaining legal advice for the suspect
Critically, detention throughout this period must remain necessary. The custody officer has a continuing duty to ask whether continued detention is justified. If at any point the investigation has produced sufficient evidence to charge, or the grounds for detention have lapsed, the detainee must be charged or released — even if the 24-hour period has not yet expired.
This is an important and frequently misunderstood principle. The 24-hour limit is a maximum, not a default entitlement. Investigators cannot detain a suspect for the full 24 hours simply because they have the legal authority to do so. The duty is to ensure detention continues no longer than necessary.
Chapter 4
Custody Officer Responsibilities
The custody officer plays a central and independent role in the PACE Clock framework. Under PACE, the custody officer must be a sergeant or above, and must be independent of the investigating team. This independence is deliberate — the custody officer is the detainee's statutory protector, not the investigator's assistant.
Record the Relevant Time
The clock starts the moment the custody officer books the detainee in. Accurate, contemporaneous recording is essential.
Authorise Initial Detention
The custody officer must decide, at the point of booking, whether detention is authorised. They must be satisfied there are reasonable grounds to believe detention is necessary for the purpose of securing or preserving evidence or obtaining evidence by questioning.
Conduct Regular Reviews
Detention must be reviewed at intervals specified by PACE. The custody officer (or reviewing inspector) must assess whether continued detention remains justified at each review.
Monitor Investigation Progress
The custody officer must keep themselves informed of the progress of the investigation. Where the investigation has stalled or ceased to be active, continued detention becomes harder to justify.
Ensure Detainee Welfare
Duty of care obligations run alongside detention authority. Meal intervals, rest periods, medical attention, access to legal advice, and appropriate treatment all fall within the custody officer's remit.
Release or Charge When Appropriate
When detention is no longer justified, or the time limit has expired, the custody officer must ensure the detainee is charged or released without delay. Continued detention beyond the clock without authority is unlawful.
The custody officer's role is sometimes described as being akin to a magistrate within the police station. Their authority to detain — or refuse to detain — is independent of the wishes of the investigating officers, and their decisions are subject to legal challenge through judicial review and claims for unlawful detention.
Chapter 5
Mandatory Detention Reviews
One of the core mechanisms through which the PACE Clock is enforced is the system of mandatory detention reviews. These reviews are not discretionary — they are legal requirements under Section 40 of PACE, and failure to conduct them in accordance with the prescribed timetable may render continued detention unlawful.
| Review | When Required | Reviewer |
|---|---|---|
| 1st Review | No later than 6 hours after detention began | Inspector or above |
| 2nd Review | No later than 9 hours after the first review (15 hours total) | Inspector or above |
| 3rd Review | No later than 9 hours after the second review (24 hours total) | Inspector or above |
| Extended Detention Reviews | Every 9 hours during any superintendent-authorised extension | Superintendent or above |
| Further Detention (Magistrates) | Court determines review schedule under the warrant | Magistrates' Court |
At each review the reviewing officer must consider whether:
The grounds for detention still exist
Continued detention is still necessary for the purpose for which it was authorised
The investigation is being conducted diligently and expeditiously
The detainee should be charged or released
Any conditions of detention require amendment (welfare, medical, etc)
The detainee and their solicitor have the right to make representations at each review. These representations must be considered and addressed. The reviewing officer may conduct the review in person or, in certain circumstances, by telephone — but the review must be genuine and not perfunctory.
⚠ Consequences of Late Reviews
A review conducted late — even by a few minutes — may render the period of detention between the due review time and the actual review time unlawful. This can affect the admissibility of any evidence obtained during that window, and may ground a civil claim for unlawful detention. Officers must build the review schedule into custody management from the outset.
Chapter 6
Extending Detention to 36 Hours
Where the initial 24-hour period is insufficient for a complex or serious investigation, Section 42 of PACE provides a mechanism for extending detention. This extension requires the personal authorisation of a superintendent (or above) and is subject to strict conditions.
The Three Conditions for a Section 42 Extension
Indictable Offence
The offence for which the person is detained must be an indictable offence. Summary-only offences cannot attract a superintendent extension. This is a hard jurisdictional limit — if the offence is summary-only, 24 hours is the maximum, full stop.
Necessity
Further detention must be necessary to secure or preserve evidence relating to an offence for which the suspect is under arrest, or to obtain such evidence by questioning. The superintendent must be genuinely satisfied on this point — a formulaic belief is insufficient.
Diligence and Expedition
The investigation must be being conducted diligently and expeditiously. If investigators have been inefficient or have failed to make reasonable progress, this condition will not be met. The extension is not a reward for slow investigation.
The superintendent authorisation must be given before the 24-hour period expires. It cannot be applied for retrospectively. If the 24-hour period expires without a Section 42 authorisation, the detainee must be immediately charged or released.
The Section 42 authorisation can extend detention up to a maximum of 36 hours from the relevant time. The superintendent cannot authorise detention beyond 36 hours — any further extension requires an application to the magistrates' court.
The detainee must be informed of the grounds for any extension and, if they have a solicitor, their solicitor must be informed. The detainee and solicitor may make representations before the decision is made.
Chapter 7
Magistrates' Court Extensions — Up to 96 Hours
For the most serious investigations, Section 43 of PACE provides a mechanism for applying to a magistrates' court for a warrant of further detention. This is the most significant step in the PACE Clock framework because it involves judicial oversight — an independent court must be satisfied that continued detention is justified.
Who Applies and When
Applications for a warrant of further detention are made by the police to a magistrates' court. The application must be made before the 36-hour period expires (i.e. before the superintendent extension runs out). If the court is not sitting and cannot be convened by that time, the suspect must be charged or released — there is no provision for informal extension pending a court hearing.
First Warrant of Further Detention
Magistrates may grant a warrant authorising additional detention. The total detention period including any Section 42 extension cannot exceed 96 hours from the relevant time. A single warrant may cover the entire remaining period, or may be for a shorter duration.
Extended Warrants Under Section 44
If the initial warrant of further detention does not take the total to 96 hours, police may apply for an extension of that warrant under Section 44 PACE. Again, the magistrates must be satisfied that the conditions for further detention are met.
The Absolute 96-Hour Maximum
No matter how many warrants are obtained or how serious the offence, total detention under PACE cannot exceed 96 hours from the relevant time. At 96 hours, the suspect must be charged or released — this is an absolute statutory limit with no exception under standard PACE powers.
What Magistrates Must Find
Magistrates hearing a further detention application must be satisfied that:
There are reasonable grounds to believe the suspect has committed an indictable offence
Further detention is necessary to secure or preserve evidence, or to obtain evidence by questioning
The investigation is being conducted diligently and expeditiously
It would not be appropriate to charge the suspect with the offence at the current stage
The suspect is entitled to be present at the hearing and to be legally represented. This is one of the relatively rare instances where a criminal suspect has an immediate right to a court hearing while still in police custody. The principle of habeas corpus — that detention must be justified before a court — is directly engaged.
Chapter 8
When the PACE Clock Can Pause
The PACE Clock runs continuously from the relevant time, but the legislation provides for a small number of specific circumstances in which the clock may be suspended. These provisions exist to prevent the unfairness that would result if unavoidable external events were to eat into investigation time.
Hospital Treatment
Where a detainee is taken to hospital for medical attention, the time spent at hospital does not automatically count against the detention clock. However this exclusion is not straightforward — it applies only to periods when the detainee is actually receiving treatment or waiting for treatment, and not simply being observed or monitored. Detailed record-keeping is essential.
Transfer Between Stations
Where a detained person is transferred between police stations, time spent in transit counts against the clock. The clock does not pause simply because the detainee is in a police vehicle. Officers should factor transit time into their detention management planning.
Appearance Before Court
Where a suspect is brought before a court during their period of detention (for example for a warrant of further detention hearing), time taken up by court proceedings is generally accounted for within the overall structure of the PACE scheme. The clock framework is designed to accommodate necessary court appearances.
Escape from Custody
If a detained person escapes from lawful custody, the period of escape does not count against the PACE Clock. When the person is re-detained, the clock resumes from the point of escape. This prevents suspects from engineering their own release through escape.
In all cases where the clock is argued to have paused, the burden falls on the custody record to justify that position. Gaps or inconsistencies in custody records are routinely challenged by defence solicitors and will be scrutinised by courts in any application alleging unlawful detention.
Chapter 9
Interview Time and the Clock
One of the most operationally important aspects of the PACE Clock for investigators is that interview time counts against the detention period. The clock does not pause while an interview is taking place. This creates significant time management challenges in complex investigations.
Why This Rule Matters
If the clock paused during interviews, investigators could conduct marathon interview sessions while effectively extending the detention period indefinitely. The rule that interview time counts against the clock prevents this and ensures investigators plan their interviews efficiently within the available time.
Operational Implications
In a 24-hour detention period, investigators must account for all other custody procedures — booking in, legal advice, forensic analysis, rest periods, meal breaks, reviews — alongside the interview itself. A complex interview strategy must be planned to fit within whatever practical window remains after these obligations are met.
This is one reason why voluntary interviews are increasingly used for complex investigations. Where a suspect attends voluntarily, there is no PACE Clock running. Investigators can take the time needed for a thorough interview without the pressure of a ticking custody clock.
For arrests, however, the clock is always running. Experienced custody officers and investigating officers will plan out the entire anticipated detention period — timing interviews, forensic results, legal advice, review points, and extension applications — to make the best possible use of available detention time.
Chapter 10
Bail and Release Under Investigation
When the PACE Clock reaches its limit — or when continued detention is no longer justified — investigators have two main options for ensuring the investigation can continue without the suspect in custody: pre-charge bail and release under investigation.
Pre-Charge Bail
Pre-charge bail allows a suspect to be released from custody on conditions, with an obligation to return to a police station on a specified date. The Policing and Crime Act 2017 introduced a 28-day default limit for pre-charge bail, extendable in certain circumstances. Bail conditions may include restrictions on travel, restrictions on contact with witnesses, or requirements to report to a police station. Breach of bail conditions is an offence and can result in re-arrest.
Release Under Investigation (RUI)
Release under investigation is an alternative introduced because pre-charge bail created problems where investigations were unlikely to be completed within the initial 28-day period. A suspect released under investigation has no bail conditions and no return date. They are simply released and informed the investigation continues. RUI has been criticised for leaving suspects in a prolonged state of uncertainty and for removing the time pressure that bail return dates created for investigators.
The choice between bail and RUI is a significant investigative decision. Bail is more appropriate where the investigation is likely to conclude within the bail period, where conditions are needed to protect witnesses or evidence, or where a return date is operationally valuable. RUI is more appropriate where the investigation is complex, lengthy, or where the evidence picture is unclear.
Neither bail nor RUI pauses the PACE Clock — the clock only applies to periods of actual custody. Once released, the clock does not continue running. If the suspect is re-arrested, a new relevant time is established and a new clock begins.
Chapter 11
Terrorism: Different Rules Apply
The PACE Clock framework described throughout this guide applies to the vast majority of criminal investigations in England and Wales. However, terrorism investigations operate under a fundamentally different statutory framework.
Terrorism Act 2000 — Separate Regime
Persons detained under terrorism powers pursuant to the Terrorism Act 2000 are subject to different detention limits. Initial detention may be up to 48 hours. Extensions of up to 14 days may be granted with judicial approval. The ordinary PACE Clock framework does not apply to these detentions. The extended limits reflect the unique investigative challenges of terrorism cases, particularly around intelligence exploitation and international coordination.
The practical implication is that officers who arrest a suspect under terrorism powers — rather than under standard PACE powers — must apply a completely different custody framework. Mixing up the regimes is a significant risk. Legal advice about which regime applies should be obtained before detention begins in any case with a potential terrorism dimension.
Chapter 12
Common Misconceptions
"Police can hold you for as long as they like while investigating"
Strict statutory time limits apply under Section 41 PACE. The maximum without charge under standard powers is 96 hours, and this requires both superintendent and magistrates' court authorisation. The vast majority of suspects are released within 24 hours.
"The PACE Clock stops running during interviews"
Interview time counts against the detention clock. Investigators must plan their entire custody strategy — including interviews, forensic waits, legal advice, and rest periods — within the running clock.
"Police have to keep you for the full 24 hours before deciding"
24 hours is a maximum, not a minimum. If the investigation concludes before the clock expires — whether by charging or by the evidence justifying release — the suspect must be released at that point.
"Detention reviews are just paperwork"
Detention reviews are substantive legal requirements. A review conducted late or without genuine consideration renders the period of detention from the due review time potentially unlawful. They are grounds for Section 78 applications and civil claims.
"Only serious offences are subject to the PACE Clock"
The 24-hour initial limit applies to all offences. Only the extension mechanisms (36 and 96 hours) are restricted to indictable offences. For summary-only offences, 24 hours is the absolute maximum.
Chapter 13
Worked Examples
Suspect arrested for theft. Arrives at police station. PACE Clock starts. Relevant time: 14:00.
Booked into custody. Legal advice requested. Duty solicitor contacted.
First review due by 20:00 (6 hours from 14:00).
Interview commences following legal consultation.
Interview concludes. Evidence reviewed.
Charged with theft and bailed. PACE Clock stops. Total detention: 5.5 hours.
In this case the investigation concluded comfortably within the 24-hour period. The suspect was charged and released on bail well before the clock expired.
Suspect arrested for serious fraud. Relevant time: 08:00.
First detention review (6 hours). Detention authorised to continue.
Second review (9 hours after first). Investigation ongoing — forensic results awaited.
23.5 hours into detention. Superintendent contacted. Section 42 extension authorised to 36 hours (deadline: 20:00 day 2).
Forensic results received. Charging decision made. Suspect charged at 31 hours.
The superintendent extension allowed the investigation to continue while awaiting forensic evidence. Charge occurred within the extended 36-hour limit.
Suspect arrested for serious assault. Relevant time: 10:00.
23 hours. Superintendent extends to 36 hours. New deadline: 22:00 Day 2.
Application made to magistrates' court before 36-hour deadline.
Court hearing. Warrant of further detention granted for 24 additional hours. New deadline: 20:00 Day 3.
Investigation complete. Suspect charged at 76 hours.
The magistrates' court warrant allowed investigation to continue into day 3. Total detention was 76 hours — well within the 96-hour maximum.
Chapter 14
Operational Reality
In practice the PACE Clock creates a constant operational backdrop to every arrest in England and Wales. For custody officers managing busy suites, the custody computer system typically tracks all PACE Clock obligations automatically — flagging approaching review times, extension deadlines, and release obligations.
The reality, however, is that many suspects are released well before the 24-hour limit. Research and practice data consistently shows that most custody detentions conclude within a few hours. Extended detention to 36 or 96 hours is relatively rare and is concentrated in serious and complex criminal investigations.
Most common
Suspects charged or released within 6 hours in straightforward cases
Standard complex
12–20 hours for cases requiring forensic analysis, multiple interviews, or CPS consultation
Extended detention
36 hours used in serious cases; 96 hours extremely rare and reserved for the most complex investigations
For investigating officers, the PACE Clock discipline often has a positive effect. Knowing that every hour in custody counts creates a structured urgency. Officers who plan their custody strategy carefully — timing forensics, interviews, and evidence review within a projected detention window — consistently deliver better investigation outcomes than those who treat custody as an open-ended resource.
The most common failure mode is underestimating how much non-interview time custody requires. Booking in, legal advice, meal and rest breaks, forensic waits, and review periods all consume clock time. A realistic custody plan for a complex investigation will often show that a 24-hour period, while substantial, is genuinely tight for a thorough investigation.
Section 15
Authority FAQ
Structured for featured snippet extraction. Each answer is self-contained and legally accurate.
What is the PACE Clock?
The PACE Clock is the legal framework that governs how long police can detain a suspect without charge after arrest. Under the Police and Criminal Evidence Act 1984, detained suspects are subject to strict time limits — normally up to 24 hours — after which they must be charged or released. The clock begins running the moment a suspect arrives at a police station following arrest.
When does the PACE Clock start?
The PACE Clock starts at the 'relevant time', which is when the detainee arrives at the first police station to which they are taken after arrest. This moment is officially recorded by the custody officer on the custody record. All detention time limits and review obligations run from this point.
How long can police hold someone without charge under PACE?
Under Section 41 of the Police and Criminal Evidence Act 1984, police can normally hold a suspect for up to 24 hours without charge. For indictable offences, a superintendent or above can authorise an extension to 36 hours. For very serious offences, a magistrates' court can grant warrants of further detention taking total detention up to a maximum of 96 hours from the relevant time.
Who can authorise extending detention beyond 24 hours?
An officer of superintendent rank or above can authorise an extension of detention beyond the initial 24-hour limit, up to a maximum of 36 hours. This is only permitted where the offence is indictable, further detention is necessary for the investigation, and the investigation is being conducted diligently and expeditiously. Further extensions beyond 36 hours require a warrant of further detention from a magistrates' court.
What is the maximum time police can hold someone without charge?
The maximum period of detention without charge under the Police and Criminal Evidence Act 1984 is 96 hours from the relevant time. This maximum can only be reached in serious cases through a combination of superintendent authorisation (to 36 hours) and one or more warrants of further detention granted by a magistrates' court. In practice, the vast majority of suspects are charged or released well before this limit.
Can the PACE Clock be paused?
Yes, the PACE Clock can be paused in limited specific circumstances. The relevant time may be delayed if a detained person is taken to hospital for medical treatment or if the suspect cannot be immediately dealt with due to circumstances beyond the custody officer's control. The clock resumes when the detainee returns or becomes available. These pauses must be carefully recorded on the custody record.
What happens when the PACE Clock expires?
When the PACE Clock expires, the suspect must either be charged with an offence or released from detention. If the suspect is released, they may be released on bail (with conditions if necessary) or released under investigation (RUI) if the investigation requires further work. Continued detention after the clock has expired without lawful authorisation constitutes unlawful detention.
How often must custody detention be reviewed?
PACE requires regular reviews of detention to ensure continued detention remains lawful and necessary. The first review must take place no later than six hours after detention began. Subsequent reviews must occur at intervals of no more than nine hours. Reviews are conducted by an inspector or above (or by the superintendent authorising extended detention). The detainee or their solicitor may make representations at each review.
Section 16
Statutory Framework
PACE 1984 — S.40
Mandates periodic reviews of detention. First review within 6 hours; subsequent reviews every 9 hours.
PACE 1984 — S.41
Establishes the initial 24-hour detention limit from the relevant time. Applies to all offences.
PACE 1984 — S.42
Superintendent extension mechanism for indictable offences. Extends limit to maximum 36 hours from relevant time.
PACE 1984 — S.43–44
Magistrates' court warrants of further detention. Absolute maximum of 96 hours from relevant time.
Conclusion
Time-Limited.
Strictly Governed.
The PACE Clock is one of the most important legal safeguards in the UK criminal justice system. It protects individuals from indefinite detention by imposing strict, legally enforceable time limits on how long police can hold a suspect without charge.
From the initial 24-hour limit, through superintendent extensions to 36 hours, to the judicially supervised maximum of 96 hours, the framework ensures that every hour of detention is justified and that independent oversight increases as detention lengthens.
For practitioners — custody officers, investigating officers, and legal advisers — the PACE Clock demands careful, structured management of every custody period. The consequences of getting it wrong extend beyond administrative correction: unlawful detention is actionable, evidence may be excluded, and the integrity of the entire investigation can be undermined.
For members of the public, understanding the PACE Clock provides the knowledge to challenge detention that exceeds lawful limits and to understand the rights that exist throughout the custody process.
Police Law Intelligence
Stay Updated on
Custody Law & PACE
Follow Police Pay on LinkedIn for authority-level analysis of custody law, PACE time limits, and detention rights in the UK.
Related Authority Guides
Continue your study of PACE powers and custody law
Section 24 PACE — Police Power of Arrest
When and why police can arrest without a warrant
Voluntary Interview Explained
When police question suspects without arrest
PACE 1984 Authority Hub
Complete guide to police powers under PACE
Section 24A — Citizen's Arrest
When members of the public can detain a suspect
Detention Limits After Arrest
Deep dive into the 24, 36, and 96-hour PACE clocks
Stop and Search Authority
Section 1 PACE, Section 60, and GOWISELY explained