Legal professional privilege: when it can be lost, waived or challenged

A right that looks stronger than it is

Legal professional privilege is one of the most robust protections in English law. It allows clients to speak candidly to their lawyers without fear that those communications will later be used against them, and courts have repeatedly described it as a fundamental right rather than a mere rule of evidence. But privilege is not a blanket immunity that covers anything a lawyer touches. It has defined boundaries, and a significant amount of litigation in England and Wales is spent arguing about exactly where those boundaries sit.

This matters commercially as much as it does academically. Businesses conducting internal investigations, regulators seeking documents, and parties in litigation disclosure all regularly clash over whether a particular document is genuinely privileged or whether the protection has been lost, waived, or never applied in the first place.

The two types, and why the distinction bites

English law recognises two forms of privilege. Legal advice privilege covers confidential communications between a lawyer and client made for the purpose of giving or receiving legal advice. Litigation privilege covers confidential communications between a lawyer, client or third party made for the dominant purpose of pending or contemplated litigation.

The distinction matters because legal advice privilege is narrower than many people assume. Courts have held that the ‘client’ for these purposes can mean only the small group of individuals within an organisation actually instructed to seek advice, not every employee who happens to correspond with the legal team. A note from a junior employee to in-house counsel describing events may not attract legal advice privilege at all if that employee was not part of the instructing client group, even though it might attract litigation privilege if proceedings were sufficiently in contemplation.

This is why organisations facing potential disputes are often advised to formalise who is authorised to instruct lawyers and to be precise about when litigation becomes ‘contemplated’ rather than merely possible, since litigation privilege only bites once that threshold is crossed and the dominant purpose of the communication is genuinely litigation, not business as usual.

The crime-fraud exception

Privilege does not protect communications made in furtherance of a crime or fraud, regardless of whether the client or the lawyer knew that was the purpose at the time. This is often called the iniquity exception. It exists because privilege is meant to encourage honest disclosure to a lawyer for the purpose of obtaining lawful advice, not to provide cover for wrongdoing dressed up as legal consultation.

The threshold is not trivial suspicion. Courts require a strong prima facie case that the communication was part of, or in preparation for, the iniquity before privilege will be overridden. This exception is frequently invoked, and frequently contested, in fraud litigation and in regulatory investigations where a party alleges that legal advice was sought to structure or conceal unlawful conduct rather than to comply with the law.

Waiver: how privilege can be given away

Privilege belongs to the client, not the lawyer, and only the client can waive it. Waiver can be explicit, such as voluntarily disclosing a privileged document to a regulator or in court proceedings, or it can be implicit, arising from conduct that is inconsistent with maintaining confidentiality.

A common trap is partial or selective disclosure. If a party discloses part of a privileged document or relies on the gist of legal advice to support its position in litigation, it can be found to have waived privilege over the whole document or the wider category of related advice, because courts are cautious about allowing parties to deploy privileged material selectively as a sword while still using privilege as a shield. Sending privileged material to a third party outside a limited, controlled purpose can also destroy the confidentiality on which the privilege depends, since privilege cannot survive without confidentiality.

Internal investigations and regulators

Internal investigations sit at the centre of much modern privilege disputes. When a company investigates alleged misconduct, interview notes, investigation reports and communications with external counsel may or may not attract litigation privilege depending on whether litigation or an adversarial regulatory process was genuinely in contemplation at the time, and whether the dominant purpose test is satisfied. Investigations conducted purely to understand what happened, with legal advice being only one of several purposes, have been found in some cases not to attract privilege at all.

Regulators such as the Financial Conduct Authority and the Serious Fraud Office can request documents during investigations, and disputes over whether specific material is privileged are common and often litigated. Firms are generally advised to take specialist advice early, keep the purpose of any investigation clearly documented, and limit circulation of sensitive material, since how an investigation is set up at the outset can determine whether privilege is available later.

Practical takeaways

Privilege remains a powerful protection, but it rewards careful handling rather than assumption. Clients and in-house teams should be clear about who is instructing the lawyer, why a document is being created, and who sees it afterwards. Anyone dealing with a live dispute, an internal investigation or a regulatory inquiry where privilege may be contested should take specific legal advice, since the rules are fact-sensitive and the consequences of getting it wrong can mean losing protection over material a business assumed was safe.

For current guidance on regulatory information requests and professional conduct expectations, the Solicitors Regulation Authority and the Law Society publish practice notes that are updated as the case law develops.