By Dr Alan Aldana (VENFORT) and Matei Clej (OUTLINE Chambers, London)

In brief

Can a person be extradited to serve a sentence imposed in their absence? Yes, but only where the person unequivocally waived the right to be present, or where they will have a genuine right to a fresh determination of the case with full procedural safeguards.

What has changed? In the United Kingdom, a reform in force since 29 September 2026 makes surrender easier where the availability of a retrial is disputed. Spain’s 2025 reform concerns European Arrest Warrants between EU Member States and does not apply to surrender to the United Kingdom.

What does it mean for the defense? The critical issue is increasingly the evidence of waiver. That evidence is usually best reconstructed by lawyers working in parallel in both jurisdictions.

An entrepreneur was convicted years ago in another country after a trial he never attended. Today, he is arrested at Madrid airport or on arrival in London. The immediate question is obvious: can he be extradited to serve a sentence imposed after a trial whose date he may not even have known?

The answer turns on two questions that matter both before Spain’s Audiencia Nacional and the courts in London. Did the person waive the right to attend the trial? If not, will they be entitled to a fresh determination of the case in which they can properly defend themselves?

Between 2025 and 2026, Spain and the United Kingdom changed their laws on this issue. This article, written by a Spanish lawyer and an English barrister, both members of the Defence Extradition Lawyers Forum, explains what has changed, where the two systems differ, and why an effective defence is often built in both jurisdictions at the same time.

Why does a conviction in absentia matter so much?

A trial in a defendant’s absence is not, in itself, incompatible with human rights. The European Court of Human Rights accepts it in two situations: where the person unequivocally waived the right to be present, or where, once aware of the conviction, they can obtain a fresh determination of the merits, both as to fact and law (Sejdovic v. Italy, Grand Chamber, 2006).

The same standard matters in extradition. Before surrendering a person to serve a sentence imposed in absentia, the court must be satisfied that one of those two safeguards is present. If neither applies, surrender may have to be refused.

One point is essential: the extradition court does not decide whether the requested person is guilty. That is a matter for the trial court in the requesting state. The extradition court asks a different question: whether the request satisfies the legal requirements and whether surrender would respect the requested person’s fundamental rights.

What has changed in 2025 and 2026?

In Spain, Organic Law 1/2025, in force since 3 April 2025, turned a previously mandatory ground for refusal into a discretionary one in cases involving convictions in absentia under the European Arrest Warrant system between EU Member States (Article 33.1 of Law 23/2014). That change does not apply to surrender to the United Kingdom, which is governed by the Trade and Cooperation Agreement. The same reform also widened the circumstances in which a criminal trial in Spain may proceed without the defendant.

In the United Kingdom, the section 246 of the Crime and Policing Act 2026 came into force on 29 September 2026. It reverses the effect of the UK Supreme Court’s decision in Merticariu (2024). Under the previous approach, it was not enough that the requested person could request a retrial if obtaining that retrial depended first on a foreign court deciding that the person had not deliberately absented themselves. Under the new law, that possibility may now be sufficient.

The reform also provides that a person who was represented at trial by a lawyer is treated as having been present. In Parliament, the Government confirmed that ‘legally represented’ still requires a mandate or instructions: a court-appointed lawyer acting without the person’s knowledge does not count (HL Deb 18 March 2026, vol 854).

Arrests made before 29 September 2026 generally remain subject to the earlier regime (SI 2026/960). The date of arrest can therefore materially affect the legal analysis.

The practical consequence is that, as the availability of a retrial becomes easier to establish, greater attention falls on the evidence said to show a valid waiver of the right to attend..

What legal framework governs extradition between Spain and the United Kingdom?

Since Brexit, surrender between Spain and the United Kingdom has been governed by Title VII of the Trade and Cooperation Agreement between the European Union and the United Kingdom (Articles 596 to 632). It replaced the European Arrest Warrant framework in UK–EU relations while preserving much of its underlying structure, subject to important differences.

For the defence, the key provisions include:

• Proportionality (Art. 597): surrender must be necessary and proportionate.
• Grounds for refusal (Articles 600 and 601), including conviction in absentia (Article 601(1)(i)) and conduct committed outside the requesting state (Article 601(1)(g)).
• Fundamental-rights safeguards (Article 604(c)): where a real risk is identified, the court may require additional assurances.
• The right to be informed that a lawyer may be appointed in the state that issued the warrant (Article 609(4)), to assist the lawyer acting in the state of arrest.
• Time limit for the decision: in principle, 60 days from arrest (Article 615).

In Spain, requests from the United Kingdom are dealt with by the Audiencia Nacional. The Trade and Cooperation Agreement applies first and, where it does not regulate a point, the Spanish Extradition Act applies subsidiarily, without a final decision by the Government. Where the requested person does not consent to surrender, the Criminal Chamber decides the case. For that reason, specialist extradition counsel in Spain should be involved from the outset.

When is a person considered to have waived the right to attend the trial?

This is where the distinction between Madrid and London becomes particularly important.

The Spanish approach. Spain’s Constitutional Court set the standard in STC 132/2020, in a case concerning extradition to Colombia. Waiver cannot be presumed: it must be unequivocal. The person must have known the date and place of the trial,either through personal service or by another means that establishes that knowledge beyond doubt.

The Constitutional Court was clear that knowledge of an investigation, or even conduct suggesting an attempt to evade the authorities, is not decisive unless it is shown that the person knew when and where the trial would take place (FJ 6). We have analyzed this sentence in detail when studying the Guarantees that protect the claimant according to the Constitutional Court.

The English approach. The UK Supreme Court also requires an unequivocal waiver (Bertino, 2024), and the burden of proving it lies on the requesting state. English courts, however, may place greater weight on conduct. In Mohammed and Oprea v Romania (2025), the High Court accepted that waiver may be inferred from extreme conduct. It may be enough for the person to have known of the proceedings and charges and to have shown a clear intention to evade them, even if the date of trial was never communicated.

An example. Consider a person who leaves the country before any trial notice is served, knowing that the police are looking for them:

• In London, that conduct may support an inference that the person knew of the proceedings and deliberately sought to avoid them.
• In Madrid, STC 132/2020 allows the defence to argue that this is not enough without proof that the person knew the date and place of trial.

The prosecution may respond, with some force, that waiver can also be implied and that a person should not benefit from having deliberately frustrated service. That is precisely why these cases turn on evidence rather than assumptions.

There is also a significant defence argument in Spain. The Court of Justice of the European Union has held that the Trade and Cooperation Agreement does not establish between the European Union and the United Kingdom a relationship as special as that between Member States, and that the cooperation it provides for is not based on preserving the mutual trust that existed before Brexit (Alchaster, C-202/24, Grand Chamber, 29 July 2024, paras 70–71). The executing court must therefore examine the risk to the requested person’s fundamental rights for itself.

Article 601(1)(i) of the Agreement itself requires, as a rule, that the person was informed of the date and place of the trial. It can therefore be argued that a Spanish court should apply that requirement with the rigour of STC 132/2020.

English courts, by contrast, give Alchasterlittle weight: it does not bind them, and they continue to apply Cretu, Bertino and Merticariu (Ene v Alexandria District Court (Romania) [2026] EWHC 286 (Admin), paras. 81 to 85).

Does any appeal amount to a ‘retrial’?

No. This is one of the most common mistakes when reading an extradition request. Strasbourg requires a fresh determination of the merits, in fact and law (Colozza v. Italy, 1985). The distinction is important:

• A genuine retrial, with evidence heard again and the same defence rights available as at the original trial: sufficient.
• A full appeal on fact and law: potentially sufficient.
• A limited appeal or extraordinary review, that first requires the defendant to establish a specific procedural defect: normally insufficient. That was the approach taken by the High Court in Tribunal Judicial da Comarca de Lisboa Norte, Republic of Portugal v dos Santos [2025] EWHC 1743 (Admin).
• A merely formal possibility of appeal:insufficient.

A statement by the requesting state that a retrial is available does not end the enquiry. The defence must establish how that right operates in practice: which court hears the application, the time limit, whether enforcement of the sentence is stayed, and whether the defendant can adduce evidence and call witnesses. That assessment usually requires a lawyer in the country where the conviction was entered.

Dual defence: why lawyers are needed in both countries

An extradition case based on a conviction in absentia should not be defended only in the country where the arrest took place. The Trade and Cooperation Agreement points the same way: the requested person must be informed of their right to appoint a lawyer in the state that issued the warrant, to assist the lawyer acting in the state of arrest (Article 609(4)). The Agreement does not say whether that lawyer is covered by legal aid, and that should not be assumed.

We refer to this coordinated approach as dual defence. Each lawyer performs a different role:

• In the country of arrest, the defence challenges surrender where there is no proof of an unequivocal waiver or where the retrial said to be available does not provide the required safeguards.
• In the country of conviction, counsel obtains the original case file, checks service and notifications, identifies the lawyer who appeared at trial and verifies how any retrial or appeal mechanism works in practice.

Both lawyers work from the same factual foundation and must reconstruct three matters:

1. What the person actually knew about the trial.
2. What they were told would happen if they failed to attend.
3. Which lawyer, if any, they instructed to act on their behalf.

English case law shows why this matters, and that the outcome is not always the one expected. In Marius Ene v Alexandria District Court (Romania) [2026] EWHC 286 (Admin), the warrant stated that the defendant had been represented. Further information contradicted it: the public defender had been appointed only on the day of trial, with no mandate, and the summons had merely been posted on the courthouse door and on a web portal. The High Court held that this material could not support a finding of deliberate absence.

The appeal was nonetheless dismissed. The warrant stated, in the relevant box, that the defendant would be entitled to a retrial, and under Merticariu, that statement binds the requesting state unless there is objective, reliable, specific and up-to-date evidence to the contrary.

Three months later, the same judge found that the Romanian authority had breached its duty of candour by withholding an expert report, filed in other proceedings, stating that it would be for the Romanian courts to decide whether there would be a retrial, whatever the English courts might say (Ene v Alexandria District Court (Romania) [2026] EWHC 1432 (Admin)). The appeal has been reopened and awaits rehearing; until then, the February decision stands. Once again, what mattered was how the retrial actually works in the country of conviction.

A recent matter. Before the Audiencia Nacional provides a similar practical lesson. The individual had been arrested at a Spanish airport following an INTERPOL diffusion linked to a UK request. The first task was to read the warrant closely. That review showed that the person had not in fact been convicted: the warrant sought surrender for prosecution. The defence strategy changed from the first day. The timetable was also addressed so that UK counsel could be brought into the case. Without access to the originating proceedings, the requested person could not make a fully informed decision on whether to consent to surrender, as required by Article 611(2) of the Agreement.

An INTERPOL Red Notice is not an international arrest warrant (INTERPOL), and nor is a diffusion. Where there are signs that the system has been misused, an application to the Commission for the Control of INTERPOL’s Files can be prepared by INTERPOL Red Notice lawyers, alongside the court defence.

The lesson is methodological. First, establish exactly what judicial decision exists: investigation, charge, warrant for prosecution or conviction. Second, read that decision against the requirements of the Agreement. Third, reconstruct from the requesting state what the extradition papers do not explain. We described the same method in the context of extraditions between Switzerland and Spain. In Spain–UK cases, that coordinated approach is not merely good practice; it is expressly supported by the treaty framework.

Frequently asked questions

“I have been arrested in Spain on a UK warrant. Will I be surrendered automatically?”

No. If you do not consent, the Criminal Chamber of the Audiencia Nacional must examine the requirements and grounds for refusal under the Agreement. In principle, the decision should be taken within 60 days.

“I was convicted in my absence and did not know the date of the trial. Can surrender be refused?”

Potentially, yes, but the outcome depends on the evidence. In Spain, STC 132/2020 requires clear proof that the person knew the date and place of trial, unless a genuine retrial is guaranteed. The way service was effected is often decisive.

“Do I also need a lawyer in the country requesting my extradition?”

In many cases, yes. Article 609(4) requires that you be informed of your right to appoint one. Without assistance in the requesting state, it can be difficult to establish what decision exists, whether a genuine retrial is available or what consenting to surrender would actually mean.

“I was arrested in the United Kingdom before 29 September 2026. Does the reform apply to me?”

Generally, no. Earlier arrests remain subject to the previous regime, which imposes a stricter approach to the retrial offered by the requesting state. The position should nevertheless be checked in the individual case.

Conclusion

The reforms adopted in 2025 and 2026 have not removed the safeguards available to a person convicted in absentia, but they have changed the legal landscape. The evidence of a valid waiver of the right to attend has now acquired even greater importance in the surrender decision. That evidence is often found in the original case file in the state of conviction, not in the extradition request itself.

In these cases, early coordination between lawyers in both jurisdictions is therefore particularly important. The sooner the defence reconstructs what actually happened in the originating proceedings, the better placed it is to assess the available legal arguments.

About the authors

Dr Alan Aldana is a Spanish criminal defence lawyer, the founding partner of VENFORT Abogados and a specialist in extradition and INTERPOL matters. He is a member of the Madrid Bar (Ilustre Colegio de la Abogacía de Madrid) and of the European Criminal Bar Association, a full member of the Defence Extradition Lawyers Forum and a member of the Legal Experts Advisory Panel of Fair Trials. He is also accredited before the International Criminal Court.

Matei Clej is a barrister at OUTLINE Chambers in London and has practised at the Bar of England and Wales since 2017. His practice focuses on extradition law and includes several reported High Court decisions concerning convictions in absentia under section 20 of the Extradition Act 2003. He is authorised to accept instructions directly from members of the public under the Public Access scheme and is a member of the Defence Extradition Lawyers Forum and the Criminal Bar Association.

Official sources cited: EU–UK Trade and Cooperation Agreement · STC 132/2020 · Law 4/1985 on Passive Extradition · Crime and Policing Act 2026, s. 246 · Bertino, UKSC · Merticariu, UKSC · Ene, High Court · Alchaster, TJUE · Sejdovic v. Italy, TEDH

This article is for general information only and does not constitute legal advice on any individual case.

Confidential consultation: through VENFORT’s extradition practice.

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Alan Aldana

Founding partner and Director of the International Criminal Law Department at VENFORT Lawyers. Lawyer accredited before the International Criminal Court, with over twenty years of practice in extraditions, INTERPOL proceedings, economic criminal law, and international sanctions, assists entrepreneurs, executives, institutions, and families with interests in Europe and the Americas.