How long can pre-trial detention last in Spain?

It depends on the purpose that justified the measure and the penalty attached to the offense. The general cap is one year if the penalty does not exceed three years, and two years if it does, extendable a single time by an extension order granted BEFORE the term expires; when detention was ordered on account of a risk of destruction of evidence, the maximum is six months and no extension is admissible.

The time limits appear in Article 504 of the Criminal Procedure Act (Ley de Enjuiciamiento Criminal). What follows is the complete table, the rules for computing time, and the four points where these deadlines are most frequently breached.

What is the maximum term of pre-trial detention?

Article 504 does not set a single time limit. It sets different terms depending on which of the purposes under Article 503 justified the measure, which means the detention order must be read first to establish which term applies.

Two clarifications on the table.

The first is that the legal reference is the PENALTY ATTACHED TO THE OFFENSE, that is, the statutory sentencing range the law assigns to the offense, not the sentence sought by the Public Prosecutor in the indictment. These are different magnitudes, and confusing them distorts the calculation.

The second is that the determining purpose is the one stated in the order that ordered the detention. If the measure was ordered on account of a risk of concealment of evidence, the six-month term under paragraph 3 governs, even if other risks are invoked afterward: the purpose cannot be substituted on the fly to gain time.

From when does the term start running?

From the police arrest, not from the detention order. This is established by Article 504.5 of the Criminal Procedure Act:

"Para el cómputo de los plazos establecidos en este artículo se tendrá en cuenta el tiempo que el investigado o encausado hubiere estado detenido o sometido a prisión provisional por la misma causa" (For the purposes of computing the time limits set out in this article, the time during which the suspect or accused has been under arrest or subject to pre-trial detention for the same case shall be taken into account.)

The Constitutional Court reiterated this recently in STC 3/2025, of 13 January 2025 (Second Chamber, recurso de amparo (a constitutional appeal for protection of fundamental rights) 6751-2022), which granted the amparo precisely because the challenged decisions had excluded TWO DAYS of police custody from the computation. The person was arrested on 16 July 2020 and brought before the court on 18 July; both periods must be counted.

Two days may seem trivial, and they are not. When an extension is ordered close to the deadline, those two days decide whether the extension arrived in time or too late, and with it whether the subsequent detention is legitimate. It is therefore advisable to reconstruct the computation from the police report, not from the detention order.

Can pre-trial detention be extended? How many times?

Only once. Article 504.2 refers to A SINGLE EXTENSION, and its length depends on the penalty attached to the offense: up to two years when the penalty exceeds three years, up to six months when it does not.

The extension further requires a reasoned order and a hearing under the terms of Article 505, and is only appropriate when circumstances arise making it foreseeable that the case cannot be tried within the initial term. It is not enough to note that the trial has not been held: the court must reason why it cannot be held in time.

What happens if the extension is granted out of time?

It is invalid. A late extension does not cure the excess, and the Constitutional Court has stated this with unusual firmness. STC 98/2002, of 29 April 2002 (First Chamber, recurso de amparo 2131/2001), puts it this way:

"ha de adoptarse antes de que el plazo inicial haya expirado, pues la lesión en que consiste el incumplimiento del plazo no se subsana por el intempestivo acuerdo de prórroga adoptado una vez superado éste" (the extension must be granted before the initial term has expired, since the violation resulting from the failure to meet the deadline is not cured by an untimely extension order issued once that deadline has already passed.)

The same doctrine is reiterated in STC 121/2003, of 16 June 2003, and in the STC 3/2025 already cited. The defect is not curable: once the term has expired without a valid extension, the detention becomes illegitimate and a later order does not rehabilitate it.

Hence the first check on any extension is the simplest one: the DATE OF THE ORDER against the expiry date calculated from the arrest.

Can delays stop the clock?

Only if they are declared when they occur and by means of a specific decision. Article 504.5 excludes from the computation any time during which the case suffered delays not attributable to the Administration of Justice, but that exclusion does not operate automatically and cannot be applied retroactively.

STC 98/2002 criticized the trial court for not having ordered

"expresamente, mediante una resolución específica y motivada, la suspensión del plazo en el momento en que las dilaciones se produjeron" (expressly, by means of a specific and reasoned decision, the suspension of the term at the moment the delays occurred.)

The practical consequence is twofold. Delays cannot be deducted once the term has already expired, nor can the excess be justified by invoking delays that no one declared at the time. If the case file does not contain the order suspending the computation at the moment the delay occurred, the time counts in full.

What if there is already a conviction under appeal?

Article 504.2 provides that, where a conviction has been handed down and has been appealed, pre-trial detention may be extended up to HALF OF THE SENTENCE ACTUALLY IMPOSED in the judgment.

The reference here ceases to be the abstract statutory range for the offense and becomes the specific sentence handed down, which in practice can considerably reduce the cap compared with the one that applied during the investigation stage.

What happens once two-thirds of the maximum term have elapsed?

An acceleration mechanism is triggered that is almost never invoked. Article 504.6 requires that, when pre-trial detention exceeds two-thirds of its maximum duration, the court and the Public Prosecutor's Office must notify, respectively, the President of the Governing Chamber and the Chief Prosecutor, for the purpose of adopting the measures necessary to give the proceedings maximum expedition. It adds that, to that end, the processing of the case shall take priority over all others.

This is an obligation to be fulfilled of the court's own motion, not upon request, and its fulfilment usually leaves no trace in the case file. Expressly requesting that this notification be verified once the threshold has been exceeded, and that it be recorded, produces two useful effects: it activates the statutory priority in scheduling and it documents the excessive duration for purposes of an appeal.

The two-thirds thresholds are as follows: EIGHT MONTHS when the cap is one year, SIXTEEN MONTHS when the cap is two years, and FOUR MONTHS when the cap is six months. If an extension has been granted, the calculation is made on the resulting maximum duration.

What can be done if the term has been exceeded?

Exceeding the maximum term results in release, without preventing detention from being ordered again if the suspect, without legitimate cause, fails to appear at any judicial summons, under Article 504.4.

The remedy is to apply for release before the investigating judge and, if refused, to lodge the appeal under Article 507, which is given priority processing as it affects a fundamental right. In summary proceedings (procedimiento abreviado) it is not necessary to first lodge a recurso de reforma (an application for reconsideration filed with the same court that issued the order, prior to any appeal).

Before raising it, it is advisable to verify these five points, in this order:

— The actual starting date of the computation, taken from the police report and not from the detention order.

— The specific purpose invoked by the order that ordered the measure, on which the applicable term depends.

— The penalty attached to the offense for which detention was ordered, not the sentence sought by the prosecution.

— If there was an extension, the date of the order granting it against the expiry date.

— If delays are to be deducted, whether the case file contains the order that declared them at the time.

Legislation and case law cited

Articles 503, 504, 505 and 507 of the Criminal Procedure Act. STC 98/2002, of 29 April (First Chamber, recurso de amparo 2131/2001). STC 121/2003, of 16 June (Second Chamber). STC 3/2025, of 13 January (Second Chamber, recurso de amparo 6751-2022). STC 19/1999, of 22 February (Second Chamber).

This guide reflects the regime in force at the date of publication and does not replace advice on a specific matter, in which the computation always depends on the case file.

Álvaro Heredia Lara. Criminal defense lawyer, member No. 10,846 of the Bar Association of Málaga (Ilustre Colegio de Abogados de Málaga). Practices in Marbella in matters of pre-trial and provisional detention, offences against public health, and extradition.