This guide is maintained as a current resource for September 2026 and covers only the laws of England and Wales. Information is for general guidance, not legal advice. Consult a qualified solicitor for advice specific to your situation.
A detailed guide to conspiracy in England and Wales: what constitutes the criminal offence under the Criminal Law Act 1977, the elements of conspiracy, common examples such as conspiracy to commit fraud or murder, how cases are prosecuted, potential penalties, and practical considerations for defendants and solicitors.
Conspiracy in criminal law refers to an agreement between two or more people to pursue a criminal course of conduct. In England and Wales, the offence of conspiracy is prosecuted even if the planned crime is never carried out, because the agreement itself constitutes the criminal act. This concept forms part of inchoate (pre‑emptive) criminal law, which targets preparatory conduct that demonstrates clear criminal intent. Understanding conspiracy is important for solicitors, students, victims of conspiratorial crime, and members of the public interested in how the justice system addresses organised or planned criminal activity.
What Is Conspiracy Under English Law?
Under section 1 of the Criminal Law Act 1977, a person commits the statutory offence of conspiracy if they:
- Agree with one or more persons to pursue a course of conduct; and
- The agreed course of conduct, if carried out in accordance with the parties' intentions, would necessarily involve the commission of one or more criminal offences by one or more participants, or would do so but for circumstances that make the offence impossible.
The essence of the offence lies in the agreement itself, not the completion of the crime that was planned. This means that even if the underlying offence does not take place, the conspirators can still be charged once agreement is established.
Key Elements of Conspiracy
Agreement Between Parties
For a conspiracy charge, there must be two or more individuals who have reached a common understanding or pact to pursue unlawful conduct. A single person acting alone cannot be guilty of conspiracy, because there is no agreement.
Intention to Commit a Crime
Both the prosecution and the courts must show that the individuals intended to be parties to the agreement and that the agreed course of conduct would, if carried out, lead to a criminal offence. This requires evidence of the mens rea - the mental element - for the conspiracy, separate from the mental element of the offence that was planned.
The Underlying Offence
The planned conduct must be capable of amounting to a criminal offence in England and Wales. For example, agreeing to rob a bank, to import illegal drugs, or to commit violent acts can all constitute conspiracy. The agreement need not specify every detail of the plan, but there must be a clear understanding among conspirators of the criminal purpose.
No Requirement for Further Action
One distinguishing feature of conspiracy compared to other preparatory offences (such as attempt) is that no additional acts in furtherance of the plan are required for liability. The offence completes at the moment the agreement is made.
Exceptions to Conspiracy Liability
The law recognises certain limited exceptions where an agreement cannot form the basis of a conspiracy offence. These include:
- Agreements solely between spouses or civil partners;
- Agreements involving a person under the age of criminal responsibility;
- Agreements that involve only the intended victim of the planned crime.
Common Types of Conspiracy Offences
Conspiracy can apply to virtually any criminal offence. Some common examples include:
- Conspiracy to commit fraud - an agreement to dishonestly obtain property, money or services.
- Conspiracy to murder - planning an unlawful killing, even if the act is never attempted or carried out.
- Conspiracy to supply drugs - agreeing to import, distribute or supply controlled substances.
- Conspiracy to engage in serious organised crime - such as trafficking, money laundering or terrorism‑related conspiracies.
Because conspiracy is concerned with planning rather than execution, many different underlying offences can give rise to conspiracy charges. The specific offence with which the planned conduct is associated will often influence both prosecution strategy and potential sentencing outcomes.
How Conspiracy Cases Are Prosecuted
A conspiracy charge is typically prosecuted in the Crown Court, reflecting the seriousness of the offence and its often complex, multi‑party nature. Prosecutors must present evidence that shows:
- An agreement existed;
- The parties intended to pursue a criminal course of conduct; and
- The agreement was capable of involving offences under the law of England and Wales.
Because conspiracies are often conducted in secret, prosecutors may rely on circumstantial evidence - such as communications, financial transactions, or actions taken by participants - to infer the agreement.
Penalties for Conspiracy
There is no single fixed penalty for conspiracy in English law. Instead, the sentence generally reflects the seriousness of the underlying criminal purpose. If the planned offence carries a high maximum sentence, the court may impose a commensurate punishment for the conspiracy. For example:
- Conspiracy to commit a serious violent or drug trafficking offence may attract lengthy custodial sentences.
- Lesser conspiracies may result in shorter custodial terms, community orders, or fines, depending on culpability and harm.
The precise sentencing range is informed by sentencing guidelines, which consider factors such as planning, leadership roles, harm, and realisation of the risk posed by the conspiracy.
Defences and Practical Considerations
Because conspiracy is based on agreement, a defendant might challenge prosecution evidence on the basis that no genuine agreement existed, or that they lacked sufficient understanding or intention to be a party to the unlawful plan. Circumstantial evidence must be carefully examined.
Additionally, individuals accused of conspiracy should consider seeking early professional legal advice from a qualified solicitor experienced in serious criminal litigation. Skilled representation can assist with pre‑charge procedures, bail applications, disclosure of evidence, and trial preparation.
Common Questions About Conspiracy
Is conspiracy the same as attempt?
No. Conspiracy is about the agreement to commit a crime. An attempt requires an action beyond mere preparation towards putting the plan into effect.
Can you be guilty of conspiracy if the crime never happens?
Yes. The offence is complete once the agreement to pursue the criminal conduct is made, even if the underlying crime never occurs.
Does conspiracy require evidence of planning steps?
Not for the offence itself - the agreement is sufficient - but prosecutors often use evidence of actions taken in furtherance of the plan to support the existence of the agreement.
Key Takeaways
In England and Wales, conspiracy is a statutory criminal offence created by the Criminal Law Act 1977. It arises where two or more people agree to pursue a course of conduct that would involve the commission of a criminal offence if carried out according to their intentions. The offence is complete at the point of agreement, regardless of whether the planned crime is attempted or completed. Conspiracy covers a wide range of criminal plans, including fraud, drug offences, violent crimes and terrorism‑related conspiracies. Because it targets criminal intent and planning, conspiracy plays a vital role in prosecuting organised and coordinated wrongdoing. Individuals facing conspiracy allegations should understand the legal elements, possible defences, and the importance of qualified legal representation.
