Guide
Part 35 questions to experts
Once a report has been served, the other side may put written questions to the expert who wrote it. The rule is narrow, the window is short, and the answers become part of the report.
Where the rule applies
England and Wales, not the whole UK
CPR 35.6 is part of the Civil Procedure Rules 1998, and rule 2.1 applies those rules to proceedings in the County Court, the High Court and the Civil Division of the Court of Appeal — courts of England and Wales.
Scotland has a separate legal system with its own rules of court, and Northern Ireland has its own too. Neither is governed by Part 35, so the procedure described here should not be applied to an instruction in either without checking the rules that do govern it.
The sequence
How the process runs
-
Report served
The clock starts
The window for putting written questions runs from service of the expert’s report, not from the date the report was written.
-
Within 28 days
Questions are put
A party may put written questions to the other side’s expert, or to a single joint expert, once and within 28 days of service. Beyond that, questions need the agreement of the other party or the permission of the court.
-
Scope
Clarification only
The questions must be for the purpose of clarifying the report, unless the court gives permission or the other party agrees otherwise. They are not an opportunity to reopen the instruction or to argue the case with the expert.
-
On answering
The answers join the report
The expert’s answers are treated as part of the report. They carry the same duty to the court and the same weight as the document they attach to.
-
If unanswered
The court can act
Where an expert does not answer, the court may direct that the party who instructed them cannot rely on that evidence, or cannot recover the expert’s fees from the other party.
In practice
What separates a useful question from a wasted one
Ask about the reasoning
A question that asks how the expert moved from finding to conclusion clarifies the report. One that asks them to adopt a different conclusion does not.
Name the paragraph
Questions tied to a numbered paragraph get answered against that paragraph. Broad questions produce broad answers.
Watch the range of opinion
If the report gives a range, asking why the expert landed where they did is clarification. Asking them to prefer the other end is not.
Keep the count honest
The entitlement is to one set of questions. A long list sent in the hope of a second bite tends to attract an objection rather than an answer.