When do you need an expert?
An expert witness is appropriate where a matter turns on issues outside the court's ordinary knowledge — technical, scientific, financial or sector-specific questions. The role is to assist the court with objective, independent opinion, not to advocate for the party instructing them.
Single joint expert or party-appointed?
Depending on the matter and the court's directions, parties may agree a single joint expert, or each side may instruct its own. The proportionality of expert evidence is something the court actively manages, so it's worth considering early.
What to look for
Relevant expertise is the starting point, but it isn't the whole picture. A good expert writes clearly, understands the boundaries of their own competence, and can withstand cross-examination. Prior experience of report-writing and giving evidence helps — though genuine, well-explained expertise can matter more than a long CV of court appearances.
The expert's duty to the court
In England & Wales, expert evidence is governed by Part 35 of the Civil Procedure Rules. The expert's overriding duty is to the court, not to the instructing party, and that duty prevails over any obligation to the person paying them. A report must state the substance of instructions and contain a statement of truth. An expert who appears partisan can do real damage to a case.
Practical pointers
Define the questions you need answered before you instruct. Provide a complete, balanced set of documents. Agree scope, fees and timing in writing. And raise potential conflicts at the outset — it is far cheaper to find them now than at trial.
Want help finding the right expert for a specific matter? Tell us what you're dealing with and we'll come back with options.