In most civil disputes, each side must disclose the documents it holds that are relevant to the issues — a process called standard disclosure under CPR Part 31. But disclosure has a significant carve-out: certain categories of document are "privileged" and can be withheld even if they are directly relevant. Understanding privilege can determine whether your lawyer's advice, your settlement negotiation, or your investigation report ends up in the hands of the other side.
Legal advice privilege: keeping your lawyer's advice confidential
Legal advice privilege (LAP) protects confidential communications between a client and their lawyer made for the purpose of giving or receiving legal advice. "Legal advice" is broader than just court advice — it covers the whole of the relationship between a lawyer and client acting in that capacity, including advice on the legal implications of a proposed transaction, a letter advising on rights and obligations, and the lawyer's note of an advice meeting.
Key limits: LAP only protects communications with a qualified lawyer (solicitor or barrister) acting in their legal capacity. Internal communications — a company's HR director telling the CEO what the lawyers said — are not automatically privileged (see Three Rivers DC v Bank of England (No 5) [2003] EWCA Civ 474). Documents that existed before any legal advice was sought are not privileged merely because they were later handed to a lawyer.
The privilege glossary entry explains both heads in plain language.
Litigation privilege: protecting investigation documents
Litigation privilege (LP) protects documents and communications created for the dominant purpose of conducting actual or anticipated litigation. Unlike LAP, LP is not limited to communications with a lawyer — it can cover a party's communications with witnesses, accident investigators, or experts, provided litigation was reasonably anticipated at the time the document was created.
The dominant purpose test is strict. A document created partly for business purposes and partly for litigation will only be privileged if litigation was the dominant purpose — not merely an equal or secondary purpose. The classic example is a post-incident investigation report: if it would have been created in any event for safety review purposes, the dominant purpose may not be litigation, and the report may have to be disclosed.
Without-prejudice communications: keeping settlement talks off the record
Without-prejudice (WP) privilege protects genuine attempts to settle a dispute. Marking a letter or email "without prejudice" prevents it being used as evidence of admissions in court. The key word is "genuine" — a letter sent to harass the other side or to make unreasonable demands may not attract WP protection even if labelled. The label alone is not decisive; the court will look at the substance.
"Without prejudice save as to costs" (WPSTC) is a special variant: the communication is privileged during the substantive case but can be shown to the judge after the case is decided, when considering who should pay costs. See the WPSTC glossary entry for how Part 36 offers work in practice.
When privilege is lost: waiver and the crime-fraud exception
Waiver. Privilege belongs to the client and can only be waived by the client. Waiver can be express (deliberate) or implied (for example, by quoting from a privileged document in a pleading or statement). Selective waiver — revealing some privileged communications to support your case while withholding others — is generally not permitted. If you waive privilege over part of a document, you may have to disclose all related documents on the same subject.
Accidental disclosure. If a privileged document is inadvertently disclosed to the other side, courts have granted injunctions preventing its use. But there is no guaranteed remedy — much depends on the circumstances and how quickly the mistake was identified. Stop reading the document immediately and contact your solicitor.
Crime-fraud exception. Privilege does not protect communications made in furtherance of a crime or fraud. A client cannot instruct a solicitor to help them commit a fraud and then claim privilege over the instructions. Courts apply this exception cautiously — it requires credible evidence of the crime or fraud.
Practical tips for non-lawyers
When seeking legal advice, use a dedicated email thread or file — this makes it easier to identify privileged communications when preparing your disclosure list. Do not forward your lawyer's advice emails to colleagues who do not need to see them — unnecessary circulation risks breaking confidentiality and may be argued to amount to waiver. Mark genuine settlement offers "without prejudice" and keep them in a separate file. For the mechanics of the disclosure process, and how documents are listed, see the witness summons entry for a worked example of the documents stage of litigation.