How extradition works: what happens after a request is made

Extradition is the formal process by which one state hands a person to another so that they can be tried for an alleged offence or serve a sentence already imposed. It is a tool for dealing with cross-border crime, and it combines law, diplomacy and human rights protections. The details differ from country to country. This guide uses England and Wales as its main example and notes where other systems work differently.

What an extradition request contains

An extradition request is a formal demand from one state to another. It normally identifies the person, describes the alleged conduct and names the offence under the requesting country's law. It also sets out the evidence or the existing conviction and sentence. Where the person is wanted for trial, the papers usually include an arrest warrant or equivalent court order.

The request does not decide guilt. The courts of the country that receives it are not trying the underlying allegation. Their task is to decide whether the legal conditions for sending the person abroad are met.

Two main routes: judicial and diplomatic

Many states handle requests in different ways depending on who is asking. Within the European Union, the European arrest warrant allows a judicial authority in one member state to ask another to arrest and surrender a person. The system was designed to be quicker and less political than traditional extradition, with strict time limits and little or no role for ministers.

Since Brexit, the United Kingdom no longer takes part in the European arrest warrant scheme. Surrender between the UK and EU states now follows arrangements in the Trade and Cooperation Agreement, which were brought into domestic law and work in a similar way. Under the Extradition Act 2003, these cases are treated as Part 1 cases and are decided by the courts.

Requests from other countries, including the United States, follow the Part 2 route. They usually arrive through diplomatic channels. The Home Secretary first decides whether to certify the request, which is largely a check that the papers are in order. The case then goes to court, and the Home Secretary makes a separate final decision on surrender if the court allows it to proceed.

Arrest and the first appearance

Once a warrant is issued, the person can be arrested. In some cases a country can arrange a provisional arrest before the full request has been sent, which gives the requesting state a limited period to supply its papers.

In England and Wales, first-instance extradition cases are heard at Westminster Magistrates' Court in London. At the first appearance the judge:

• confirms that the person in court is the one named in the warrant or request;
• explains what the request alleges;
• explains that the person may consent to extradition, which can shorten the process considerably; and
• decides whether to grant bail or keep the person in custody.

Bail can be hard to obtain in extradition cases, because the court must consider the risk that the person will leave the country.

The extradition hearing

If the person does not consent, the court fixes an extradition hearing. In Part 1 cases the timetable is short. In Part 2 cases it can be several months, because the evidence and legal arguments are often more complex.

What the judge must decide

The judge checks that the paperwork is valid and that the alleged conduct amounts to an offence that can be extradited. In many cases this includes the principle of dual criminality, meaning the conduct must be a crime in both countries. The judge then considers the legal barriers to extradition raised by the defence.

Common bars to extradition

• Human rights: extradition cannot go ahead if it would breach the European Convention on Human Rights, for example through a real risk of torture or inhuman treatment, or an unfair trial.
• Proportionality: in warrant cases, the court can refuse where surrender would be out of proportion to the alleged offence.
• Passage of time: a delay can make it unjust or oppressive to send someone abroad.
• Double jeopardy: a person already finally dealt with for the same conduct may be protected.
• Health: a person's physical or mental condition may make surrender unjust or oppressive.

Many countries also refuse extradition where the person could face the death penalty, unless the requesting state gives a binding assurance that it will not be imposed.

The executive decision

In Part 1 cases the judge's ruling is the decision. In Part 2 cases, if the judge finds that the legal tests are met, the file goes to the Home Secretary. The Home Secretary considers matters such as the death penalty, whether the person could be tried for other offences not covered by the request, and whether surrender is otherwise barred. The Home Secretary's decision can itself be challenged in the courts.

Appeals and surrender

Both sides can usually challenge the outcome. A person ordered to be extradited, or the requesting state if the person is discharged, can ask the High Court for permission to appeal. The deadlines are short, counted in days, and permission is needed before an appeal can be heard. A further appeal to the Supreme Court is possible only in limited circumstances, generally where a point of law of general public importance is involved.

When all appeals are over, surrender must take place within a fixed period, unless the two sides agree a later date. Surrender can be postponed if the person faces charges or is serving a sentence in the country where they were arrested. Most countries also apply the rule of speciality, which means the person can be prosecuted only for the offences for which they were surrendered, unless the sending state agrees otherwise.

Why the process takes time

Contested cases can last many months or even years, because each stage allows legal challenges. The aim is to balance two interests: not letting borders shield people accused of serious crime, and making sure no one is sent abroad in breach of their basic rights. Every ruling in that process is open to review.