CPR Part 35 Expert Reports & Joint Statements
Experts instructed in England and Wales litigation owe paramount duties to the court under CPR Part 35 and Practice Direction 35. Reports must identify instructions, materials reviewed, key assumptions, and limitations - with fair exposition where reasonable experts disagree.
Joint meetings and joint statements isolate areas of agreement and disagreement on methodology, datasets, and quantum ranges, narrowing trial issues efficiently.
| Report element | Why it matters | Common pitfall |
|---|---|---|
| Instructions scope | Defines the question answered | Over-broad remit |
| Data lineage | Reproducible spreadsheets | Black-box models |
| Alternative assumptions | Ikarian Reefer range disclosure | False precision |
| Joint statement | Agreed facts vs opinions | Late surprises at trial |
Frequently asked questions
What are a BI expert's duties under CPR Part 35?
The expert’s paramount duty is to the court. They must provide objective opinions, disclose material facts even if adverse, and acknowledge reasonable ranges where experts disagree - per CPR Part 35 and The Ikarian Reefer principles.
What should a CPR-compliant BI report include?
Clear instructions, materials reviewed, qualifications, policy definitions used, ROGP and ICW workings, indemnity period boundaries, assumptions, limitations, and fair exposition of alternative reasonable views.
What is a Single Joint Expert (SJE) in a BI dispute?
A court may appoint one expert jointly instructed by both parties. For significant contested quantum, parties usually retain separate experts and produce a joint statement identifying agreement and disagreement.
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