Party-Appointed vs Single Joint Expert: What Solicitors Should Know

Choosing between a party-appointed expert and a Single Joint Expert (SJE) is a strategic decision with cost, tactical and case management implications. Financial experts in commercial disputes are frequently appointed on both models.

Party-appointed experts

Each party instructs their own expert. Reports are exchanged, followed often by experts' meetings and a joint statement identifying agreements and disagreements.

Advantages:

• Each party can select an expert with specific sector experience
• Independent critique of the opponent's theory via rebuttal reports
• Greater flexibility where multiple distinct financial issues exist

Disadvantages:

• Higher cost (two experts, two reports, meeting time)
• Risk of "battle of experts" if courts perceive polarised positions
• Greater solicitor time managing parallel expert processes

Party appointment is common in high-value commercial litigation where quantum is heavily contested and each side requires dedicated forensic support.

Single Joint Experts

One expert is instructed jointly (or appointed by the court) to opine on defined issues. The expert owes the same duty to the court under CPR Part 35.3.

Advantages:

• Reduced duplication and potentially lower overall expert costs
• A single opinion on technical issues may narrow trial scope
• Court encouragement in appropriate cases (see CPR 35.7)

Disadvantages:

• Joint instructions can be slow to agree
• Less adversarial testing of methodology before meeting
• If the SJE is unsuitable or the instruction is poorly framed, both parties are affected

SJEs work well where issues are discrete (e.g. a defined valuation date, a specific BI period) and both parties seek a neutral figure.

Strategic considerations

1. Complexity - Multiple interacting financial issues may favour separate experts.
2. Credibility - Select an expert with demonstrable court/arbitration experience regardless of model.
3. Timing - Early SJE appointment can accelerate settlement; late appointment may compress timetables unsafely.
4. Arbitration - Institutional rules and tribunal preferences may differ from CPR practice.

Joint instructions and disagreements

For SJEs, agree the letter of instruction in writing. If parties cannot agree, the court may determine the instruction. Experts should not accept ambiguous joint letters that silently embed one party's narrative.

Changing model mid-case

Switching from dual experts to SJE (or vice versa) is possible but disruptive. Early case assessment with forensic input helps select the right model before directions bite.

We accept both party-appointed and SJE instructions subject to conflicts. Learn more on our commercial dispute expert witness page or contact us for an initial discussion.