Legal professional privilege: how it protects client communications
A guide to the rule that lets clients speak candidly to their lawyers, why it matters, and where its limits lie.
What legal professional privilege is
Legal professional privilege is the legal principle that protects certain communications between a lawyer and their client from being disclosed to third parties, including courts, regulators and opposing parties in litigation. It is one of the oldest and most fiercely protected doctrines in English law. The idea behind it is simple: clients need to be able to tell their lawyer the whole truth, including uncomfortable facts, without fear that what they say will later be used against them. If clients held back information to protect themselves, lawyers could not give sound advice, and the justice system as a whole would suffer.
Privilege belongs to the client, not the lawyer. That means only the client can waive it, and a lawyer cannot be forced to hand over privileged material even if a court or regulator would find it useful. It is treated as a fundamental right rather than a mere rule of evidence, which is why courts are reluctant to override it except in narrow, well-defined circumstances.
The two main categories
Privilege in England and Wales is generally split into two overlapping but distinct types.
Legal advice privilege covers confidential communications between a lawyer and their client made for the purpose of giving or receiving legal advice. This applies whether or not litigation is contemplated. A company asking its solicitor whether a proposed contract clause is enforceable, or an individual asking about their rights on separation, would typically fall within this category. A key complication in corporate settings is identifying who counts as the “client” for these purposes: case law has drawn a narrow line around which employees within an organisation are treated as the client instructing the lawyer, meaning not every internal communication about a legal question is automatically covered.
Litigation privilege applies more broadly once litigation is in reasonable contemplation, meaning it is more than a mere possibility. It covers confidential communications between a lawyer and client, or between either of them and a third party such as an expert witness or investigator, provided the dominant purpose of the communication is preparing for that litigation. This is why witness statements drafted in preparation for a claim, or reports commissioned from an accountant to support a legal case, can be protected even though the accountant is not a lawyer.
Why it matters in practice
Privilege affects how organisations and individuals conduct internal investigations, respond to regulatory inquiries, and manage disputes. A business facing a potential claim, an internal fraud allegation, or a regulatory investigation will often want early input from lawyers specifically so that the resulting analysis, interviews and reports can be protected from disclosure to the other side or to a regulator. Getting this wrong, for example by commissioning an internal report before litigation is truly in contemplation, or by copying too many people into a legal advice email, can mean the protection is lost or was never available in the first place.
Privilege also matters for regulators. Bodies such as the Financial Conduct Authority or the Serious Fraud Office can compel production of many types of document, but privileged material is generally exempt from that power. Disputes over whether particular documents are genuinely privileged, rather than simply commercially sensitive, are a recurring feature of large investigations and litigation.
What is not covered
Privilege is not unlimited. It does not protect communications made in furtherance of a crime or fraud, a principle often referred to as the crime-fraud or iniquity exception. If a client seeks a lawyer’s help to commit or conceal wrongdoing rather than to obtain genuine legal advice, that communication falls outside privilege altogether.
Privilege also does not extend to facts simply because a lawyer happens to know them. If a client tells their solicitor a fact that is otherwise discoverable through other means, the underlying fact is not protected merely because it was mentioned in a privileged conversation; only the communication itself is protected. Similarly, privilege does not attach to documents that exist independently of the legal advice relationship, such as ordinary business records, simply because they are later sent to a lawyer.
Waiver and disclosure
Because privilege belongs to the client, it can be waived, whether deliberately or by accident. Sharing privileged advice with an outside party, referring to its contents in correspondence, or deploying it as part of a legal argument can all risk waiving protection, sometimes for the whole document and not just the part disclosed. This is why solicitors are careful about how privileged material is stored, labelled and circulated, and why organisations are advised to take specific legal guidance before sharing legal advice with auditors, insurers or regulators.
Where to check current guidance
The detailed rules on privilege, disclosure and how it interacts with regulatory powers can be technical and fact-specific. Anyone dealing with a live situation, particularly an internal investigation or regulatory request, should take advice from a qualified solicitor rather than relying on general guidance.