This blog looked recently at the case of O v B-M [2019] EWFC B23 where the trial judge was critical of a jointly instructed expert’s attempt to find facts and state that something was “proven by overwhelming evidence”.  That case contains important observations as to the role of the expert in these circumstances.  It most certainly is not to displace the role of he trial judge.   Here we look at the guidance available to the lawyer (and the expert) in relation to the instruction of a joint expert.


The rules give some basic guidance as to the steps to be taken when instructing a single joint expert.  Firstly CPR 35.8.

Instructions to a single joint expert


(1) Where the court gives a direction under rule 35.7 for a single joint expert to be used, any relevant party may give instructions to the expert.

(2) When a party gives instructions to the expert that party must, at the same time, send a copy to the other relevant parties.

(3) The court may give directions about –

(a) the payment of the expert’s fees and expenses; and

(b) any inspection, examination or experiments which the expert wishes to carry out.

(4) The court may, before an expert is instructed –

(a) limit the amount that can be paid by way of fees and expenses to the expert; and

(b) direct that some or all of the relevant parties pay that amount into court.

(5) Unless the court otherwise directs, the relevant parties are jointly and severally liable for the payment of the expert’s fees and expenses.


The Practice Direction is fairly light on the practical issue of instructing an expert, it provides some guidance as to when joint instruction should be considered.

“Single joint expert

7 When considering whether to give permission for the parties to rely on expert evidence and whether that evidence should be from a single joint expert the court will take into account all the circumstances in particular, whether:
(a) it is proportionate to have separate experts for each party on a particular issue with reference to –
(i) the amount in dispute;
(ii) the importance to the parties; and
(iii) the complexity of the issue;
(b) the instruction of a single joint expert is likely to assist the parties and the court to resolve the issue more speedily and in a more cost-effective way than separately instructed experts;
(c) expert evidence is to be given on the issue of liability, causation or quantum;
(d) the expert evidence falls within a substantially established area of knowledge which is unlikely to be in dispute or there is likely to be a range of expert opinion;
(e) a party has already instructed an expert on the issue in question and whether or not that was done in compliance with any practice direction or relevant pre-action protocol;
(f) questions put in accordance with rule 35.6 are likely to remove the need for the other party to instruct an expert if one party has already instructed an expert;
(g) questions put to a single joint expert may not conclusively deal with all issues that may require testing prior to trial;
(h) a conference may be required with the legal representatives, experts and other witnesses which may make instruction of a single joint expert impractical; and
(i) a claim to privilege( makes the instruction of any expert as a single joint expert inappropriate.”




More detailed guidance is to be found in the Civil Justice Council Guidance.  Note, in particular, there are procedures in place if the parties cannot agree instructions and if the expert receives instructions from one party but not the other.

“Single joint experts
34. CPR 35.7-8 and PD 35 paragraph 7 deal with the instruction and use of
joint experts by the parties and the powers of the court to order their use. The
CPR encourage the use of joint experts. Wherever possible a joint report should
be obtained. Single joint experts are the norm in cases allocated to the small
claims track and the fast track.
35. In the early stages of a dispute, when investigations, tests, site
inspections, photographs, plans or other similar preliminary expert tasks are
necessary, consideration should be given to the instruction of a single joint
expert, especially where such matters are not expected to be contentious. The
objective should be to agree or to narrow issues.
36. Experts who have previously advised a party (whether in the same case or
otherwise) should only be proposed as single joint experts if the other parties are
given all relevant information about the previous involvement.
37. The appointment of a single joint expert does not prevent parties from
instructing their own experts to advise (but the cost of such expert advisors will
not be recoverable from another party).
Joint instructions
38. The parties should try to agree joint instructions to single joint experts, but
in default of agreement, each party may give instructions. In particular, all parties
should try to agree what documents should be included with instructions and
what assumptions single joint experts should make.
39. Where the parties fail to agree joint instructions, they should try to agree
where the areas of disagreement lie and their instructions should make this clear.
If separate instructions are given, they should be copied to the other instructing
40. Where experts are instructed by two or more parties, the terms of
appointment should, unless the court has directed otherwise, or the parties have
agreed otherwise, include:
a. a statement that all the instructing parties are jointly and severally
liable to pay the experts’ fees and, accordingly, that experts’
invoices should be sent simultaneously to all instructing parties or
their solicitors (as appropriate); and
b. a copy of any order limiting experts’ fees and expenses (CPR
41. Where instructions have not been received by the expert from one or more
of the instructing parties, the expert should give notice (normally at least 7 days)
of a deadline for their receipt. Unless the instructions are received within the
deadline the expert may begin work. If instructions are received after the deadline
but before the completion of the report the expert should consider whether it is
practicable to comply without adversely affecting the timetable for delivery of the
report and without greatly increasing the costs and exceeding any court approved
budget. An expert who decides to issue a report without taking into account
instructions received after the deadline must inform the parties, who may apply to
the court for directions. In either event the report must show clearly that the
expert did not receive instructions within the deadline, or, as the case may be, at