Extradition in the UK: Defence for International Cases

The Extradition Act 2003 divides extradition partners into two categories. Category 1 territories — EU member states under the UK-EU Surrender Agreement post-Brexit, plus a small number of others — operate under an accelerated process. Category 2 territories are countries with bilateral extradition treaties with the UK, where a more standard judicial process applies.

For Category 1 (EU) cases, a European Arrest Warrant equivalent is executed: an arrest, a hearing within 21 days, and a decision by a district judge. The judge’s role is limited to verifying identity, whether the offence is extraditable, and whether any bars to surrender apply. For Category 2 cases, an additional layer of scrutiny applies: the requesting state must provide prima facie evidence of guilt, and the Secretary of State retains a final political decision-making role in some cases.

UK courts will refuse extradition on several specific grounds. Dual criminality is the threshold requirement: the conduct must constitute an offence under both UK law and the law of the requesting state. If it does not, extradition cannot proceed.

Beyond dual criminality, the available bars include: passage of time (section 14 — if it would be unjust or oppressive to extradite given the time elapsed since the alleged offence); forum bar (if a substantial measure of the conduct occurred in the UK and it would be in the interests of justice for the case to be tried there); human rights (section 21 — if extradition would be incompatible with ECHR rights, including Article 3 on torture and Article 6 on fair trial); and the rule of specialty, which limits prosecution to the offences specified in the extradition request.

UK courts can also refuse extradition where the individual would face the death penalty in the requesting state, where the request is made for political purposes, or where the individual has already been tried for the same conduct. The human rights bar has been successfully invoked in high-profile US extradition cases including Gary McKinnon, Julian Assange, and Lauri Love — each involving arguments about the conditions of detention or the disproportionate nature of the potential sentence.

Brexit ended UK participation in the European Arrest Warrant framework. The UK-EU Trade and Cooperation Agreement created a replacement mechanism: the UK-EU surrender arrangements, which apply to offences committed after January 1, 2021 for most purposes. EU member states remain Category 1 territories, but procedural changes apply. One significant change: for offences committed after December 31, 2020, EU member states may decline to surrender their own nationals to the UK, and the UK has similar discretion regarding British nationals.

The US-UK Extradition Treaty 2003 is one of the most significant bilateral arrangements in operation. Under the treaty, US requests to the UK require no prima facie evidence — only information sufficient to constitute a reasonable belief that the person committed the offence. This asymmetry has been criticised and is a significant practical factor in UK-US extradition cases. US-requested extraditions from the UK have included cases involving computer crime, financial fraud, and drugs offences where the alleged conduct had limited UK connection.

A decision by a district judge can be appealed to the High Court on questions of law. High Court decisions can be further appealed to the Supreme Court with permission. An application to the European Court of Human Rights can delay extradition while an application is pending, though the Strasbourg court’s interim measures are not automatically granted. Timing matters: applications should be made promptly, and legal representation at the earliest stage — ideally before any arrest — produces the best outcomes.

If you face extradition proceedings in the UK or are wanted by UK authorities while abroad, contact our team immediately for a confidential assessment. We handle both incoming and outgoing UK extradition cases. See also our pages on international extradition defence and countries with no extradition treaty with the UK.