Medical Evidence in Personal Injury Claims: CPR Part 35 Requirements

Author: Stevie Hayes | Last updated: March 2026

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Quick Answer

Medical evidence is governed by CPR Part 35 and its accompanying Practice Direction. In personal injury claims, the medical expert owes a duty to the court — not to the party paying their fees. Reports must comply with strict formatting and content requirements, including a statement of truth and a declaration of the expert's qualifications, instructions, and methodology. The court controls expert evidence through directions on the number of experts, whether a single joint expert is appropriate, and whether experts should hold discussions. Understanding these requirements is essential because non-compliant medical evidence can be excluded — and without medical evidence, your personal injury claim cannot succeed.

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Introduction

In personal injury litigation, medical evidence is not merely important — it is indispensable. You cannot recover general damages for pain, suffering, and loss of amenity without a medical report confirming your injuries and their cause. You cannot claim future loss of earnings without a prognosis addressing your capacity to work. You cannot quantify future care costs without expert evidence on your ongoing needs.

Yet the rules governing medical evidence are more prescriptive than many claimants — and indeed some practitioners — appreciate. CPR Part 35 imposes specific obligations on experts, specific requirements for report content, and gives the court broad powers to control how expert evidence is presented. Failure to comply can result in the evidence being excluded or given reduced weight.

This guide explains the CPR Part 35 framework in practical terms: how to instruct an expert, what the report must contain, how single joint experts work, how to put written questions to the other side's expert, and how to present medical evidence effectively in your court bundle.

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The Purpose of CPR Part 35

CPR Part 35 exists to ensure that expert evidence assists the court rather than becoming a partisan tool for the parties. Before the Civil Procedure Rules came into force in 1999, expert evidence in civil litigation was widely criticised for being adversarial rather than objective — parties would instruct "hired guns" whose reports invariably supported the instructing party's case.

The overriding principle of CPR Part 35 is stated in Part 35.3:

It is the duty of experts to help the court on matters within their expertise. This duty overrides any obligation to the person from whom experts have received instructions or by whom they are paid.

This principle has practical consequences throughout the process of obtaining and presenting medical evidence.

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Instructing a Medical Expert

Choosing the Right Expert

The expert must be qualified in the relevant medical specialty. A GP should not be providing an expert opinion on orthopaedic surgery; a psychiatrist should not be opining on neurological damage. The court will assess the expert's qualifications and experience in determining the weight to give their evidence.

For claims within the Official Injury Claim (OIC) portal, the initial medical expert must be sourced through MedCo, the Ministry of Justice's accredited portal for medical reporting organisations. For claims outside the portal, the parties have greater freedom to choose their expert, subject to the court's directions.

The Letter of Instruction

The letter of instruction is a critical document. Under Practice Direction 35, paragraph 9.1, the party instructing the expert must provide:

• The identity of the party instructing the expert
• The issues the expert is asked to address
• All material documents and records the expert needs to review
• Whether Part 36 offers or other settlement offers have been made (in general terms, without disclosing amounts)

The letter of instruction should be disclosed to the other party if requested. Courts take a dim view of letters that attempt to lead the expert towards a particular conclusion.

What to Send to the Expert

Provide the expert with:

Withholding relevant records from the expert — particularly records that might undermine the claim — is improper and likely to be discovered. If the expert later learns of omitted records, their trust in the instructing party (and their willingness to support the case) may be damaged.

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What a CPR Part 35 Compliant Report Must Contain

Practice Direction 35, paragraph 3.2, sets out the mandatory contents of an expert report. Non-compliance risks the report being excluded or given reduced weight.

Mandatory Contents

1. The expert's qualifications and experience — Including relevant publications, research, and clinical experience in the specific field

2. The substance of all material instructions — Whether written or oral. The expert must summarise what they were asked to do and what materials they were provided with

3. The facts and assumptions upon which the opinion is based — The expert must distinguish between facts they have verified and assumptions provided by the instructing party

4. A statement setting out the issues the expert was asked to address — Clearly identifying the questions posed

5. The expert's opinion on each issue — Expressed clearly and with reasons

6. A summary of the range of opinion on each issue — Where there is a range of professional opinion, the expert must acknowledge it and explain where their own opinion falls within that range

7. A statement of matters which fall outside the expert's expertise — The expert must not stray beyond their area of competence

8. Any qualification to the opinion — If the expert considers that further information or investigation is needed, they must say so

9. A statement of truth — In the following form: "I confirm that I have made clear which facts and matters referred to in this report are within my own knowledge and which are not. Those that are within my own knowledge I confirm to be true. The opinions I have expressed represent my true and complete professional opinions on the matters to which they refer."

10. A declaration — That the expert understands their duty to the court and has complied with it

Common Deficiencies in Medical Reports

Reports frequently fall short of Part 35 requirements in these ways:

• No discussion of range of opinion — The expert states their view without acknowledging that other qualified practitioners might reasonably disagree
• Failure to address causation — The report describes the injuries but does not link them to the accident
• Pre-existing conditions glossed over — If the claimant had pre-existing symptoms, the expert must address whether and to what extent the accident aggravated them
• Missing statement of truth — Without the statement of truth in the prescribed form, the report does not comply with Practice Direction 35
• Instructions not summarised — The substance of the instructions must be set out in the report

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Single Joint Experts

When Are Single Joint Experts Used?

Under CPR Part 35.7, the court may direct that evidence on a particular issue is given by a single joint expert — one expert instructed by both parties. Single joint experts are particularly common in:

• Small claims track personal injury cases
• Fast track cases where the medical issues are straightforward
• Lower-value claims where the cost of two experts would be disproportionate

In higher-value or more complex cases — particularly multi-track clinical negligence claims — each party typically instructs their own expert, with the court potentially directing the experts to hold discussions.

How Joint Instruction Works

When a single joint expert is directed:

1. Both parties agree on the expert — If they cannot agree, the court will select from a list provided by the parties
2. Both parties contribute to the letter of instruction — Each party can include their own questions, and the expert receives a single combined letter
3. Both parties share the cost equally (unless the court orders otherwise)
4. The report is addressed to the court, not to either party
5. Either party may put written questions to the expert under CPR Part 35.6

Challenging a Single Joint Expert's Opinion

If you disagree with the single joint expert's conclusions, your options are limited but not non-existent:

• Put written questions under Part 35.6 (see below)
• Apply for permission to instruct your own expert — The court may grant this if the joint expert's report raises issues that require further investigation, but this is the exception rather than the rule
• Cross-examine the joint expert at trial — With the court's permission

The court is generally reluctant to permit a party to instruct a second expert on the same issue after a joint expert has reported. You need compelling reasons — not merely that you disagree with the conclusion.

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Written Questions Under CPR Part 35.6

The Right to Ask Questions

Under CPR Part 35.6, a party may put written questions to the other party's expert (or to a single joint expert) about their report. This is a valuable but underused procedural tool.

Rules for Questions

• Questions must be put within 28 days of service of the expert's report
• Questions must be for the purpose of clarification of the report only
• Questions that seek to extend the expert's instructions or raise entirely new issues are impermissible
• The expert's answers are treated as part of the report

Effective Use of Part 35.6 Questions

Well-crafted questions can significantly strengthen your case:

Clarifying assumptions:

"In paragraph 14 of your report, you state that the claimant's symptoms are consistent with a grade 2 whiplash injury. Did you consider the GP records at page 47 of the bundle, which record persistent headaches and dizziness not typically associated with grade 2 whiplash?"

Exploring the range of opinion:

"You state that recovery from this type of injury typically takes 12-18 months. Are you aware of the literature suggesting that patients with the claimant's specific risk factors experience recovery times at the upper end of or beyond this range?"

Addressing omissions:

"Your report does not address the claimant's pre-existing lower back condition noted in the GP records. In your opinion, to what extent, if any, has the accident aggravated this pre-existing condition?"

What Happens If the Expert Refuses to Answer?

If an expert fails to answer questions within a reasonable time, the court may order that the party who instructed the expert cannot rely on the evidence of that expert, or may make such other order as it thinks just (CPR Part 35.6(4)).

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Experts' Discussions and Joint Statements

Court-Directed Discussions

Under CPR Part 35.12, the court may direct experts to hold discussions for the purpose of:

• Identifying and discussing the expert issues in the proceedings
• Reaching agreement where possible
• Identifying what remains in dispute and why

The Joint Statement

Following discussions, the experts must prepare a joint statement setting out:

• The issues on which they agree
• The issues on which they disagree
• A brief summary of the reasons for disagreement

The joint statement is a powerful document. Where experts agree, the agreed position effectively becomes the evidence on that issue — neither party can easily depart from it. Where they disagree, the joint statement frames the issues for the trial judge with precision.

Important Safeguards

• Legal representatives may attend experts' discussions only if all parties agree and the court permits it
• Discussions are not binding on the parties — a party is not bound by agreements reached by their expert
• However, departing from an expert's agreed position requires a very good reason and may attract adverse costs consequences

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Presenting Medical Evidence in Your Bundle

Organisation

Medical evidence should be presented in a dedicated section of the bundle, typically organised as follows:

1. Expert reports — In the order they were served (claimant's expert first, then defendant's)
2. Joint statement (if applicable)
3. Responses to Part 35.6 questions
4. Medical records — Chronologically, sub-divided by source (hospital, GP, imaging)
5. Rehabilitation and treatment records

Making the Evidence Accessible

Judges read bundles before the hearing. If the medical evidence is buried, disorganised, or difficult to navigate, the judge forms an incomplete picture before the trial even begins.

Practical tips:

• Tab and bookmark each expert report and each set of medical records
• Highlight key passages in the medical records that are referenced in the expert reports (if the court permits)
• Include a medical chronology — a timeline of treatment, separate from the general chronology, that the judge can use as a reference tool
• Cross-reference the expert reports to the specific pages in the medical records that support each finding

Electronic Bundle Requirements

For electronic bundles — now the norm in most courts — ensure that:

• The PDF is searchable (OCR processed)
• Bookmarks are set for each expert report and each set of records
• The index is hyperlinked to the relevant pages
• File size is optimised (avoid unnecessarily large scans)

BundleCreator.co handles these technical requirements automatically — generating searchable, bookmarked, paginated bundles from your uploaded documents with hyperlinked indices, so you can focus on the substance of your evidence rather than the formatting.

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MedCo and the OIC Portal

When MedCo Applies

For personal injury claims arising from road traffic accidents, workplace accidents, or public liability incidents where the claim is valued at or below the small claims limit (£5,000 for RTA, £10,000 for non-RTA), the initial medical report must be obtained through MedCo.

MedCo is a government-backed portal that accredits medical reporting organisations and experts. Its purpose is to ensure independence and quality in medical reporting for lower-value claims.

Key MedCo Requirements

• The claimant (or their representative) searches for an expert through the MedCo portal
• The expert is randomly selected from accredited organisations in the relevant area
• The first report must be a fixed-cost medical report
• The claimant must not be examined by a medical expert who has a financial relationship with the instructing party

Beyond MedCo

For claims above the small claims limit, or where the case exits the OIC portal, the MedCo requirements no longer apply, and parties have greater freedom to instruct experts of their choosing — subject to the court's directions and CPR Part 35.

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Common Scenarios and Practical Solutions

Pre-Existing Conditions

If you had pre-existing medical conditions before the accident, do not try to hide them. The defendant's legal team will obtain your GP records and any attempt to conceal pre-existing conditions will destroy your credibility.

Instead, provide the expert with full records and ask them to address:

• The nature and severity of the pre-existing condition before the accident
• Whether and to what extent the accident has aggravated the pre-existing condition
• The likely course of the pre-existing condition without the accident (the "but for" analysis)
• The prognosis for the aggravated condition

Multiple Injuries Requiring Different Specialists

Complex injuries may require reports from multiple specialists — for example, an orthopaedic surgeon for fractures, a neurologist for head injury, and a psychiatrist for PTSD. Each expert should address only their area of competence, but the reports should be consistent in their factual basis.

Ensure each expert has access to the other experts' reports where relevant, so that the medical evidence presents a coherent picture rather than conflicting narratives.

Deterioration After the Initial Report

If your condition deteriorates after the initial medical report, obtain an updated report. The court needs current evidence, not a snapshot from twelve months ago. The updated report should cross-reference the original and explain what has changed and why.

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Frequently Asked Questions

Can I choose my own medical expert for a personal injury claim?

For claims within the OIC portal, the initial expert must be sourced through MedCo. For claims outside the portal or above the small claims limit, you can instruct the expert of your choice, subject to the court's directions. The court may direct a single joint expert, particularly in fast track cases. In all cases, the expert must be qualified in the relevant medical specialty.

What happens if I disagree with the medical expert's report?

If you disagree with your own expert's conclusions, you should discuss the specific areas of concern with the expert before seeking a different opinion. If the expert has made factual errors or failed to consider relevant evidence, they may amend the report. You cannot, however, instruct multiple experts on the same issue without the court's permission, and "expert shopping" — obtaining reports until you find one that says what you want — is improper and may attract costs sanctions.

How long does a medical report take to prepare?

This varies considerably depending on the complexity of the case and the expert's availability. A straightforward soft tissue injury report may take 4-6 weeks from instruction to delivery. Complex cases requiring extensive record review — particularly clinical negligence cases — may take 3-6 months. Always allow sufficient time in your litigation timetable.

What is the difference between a medical report and a medical record?

A medical record is the contemporaneous clinical documentation created during your treatment — hospital notes, GP consultations, test results, nursing observations. A medical report is an expert's retrospective analysis of your condition, prepared specifically for the court, which interprets the medical records and offers an expert opinion on diagnosis, causation, and prognosis.

Can the other side's solicitor ask my medical expert questions?

Yes. Under CPR Part 35.6, any party may put written questions to any expert who has provided a report. The questions must be for clarification of the report and must be put within 28 days of service. The expert's answers are treated as part of the report. This mechanism ensures transparency and allows both parties to test the expert evidence without the expense of a full hearing.

What is a joint statement from experts?

When the court directs experts to hold discussions under CPR Part 35.12, the experts must produce a joint statement recording the issues they agree on, the issues they disagree on, and the reasons for any disagreement. The joint statement is a particularly important document because it narrows the issues for trial and often resolves peripheral disputes, allowing the hearing to focus on what genuinely remains in contention.

How should medical evidence be presented in the court bundle?

Medical evidence should occupy a dedicated section of the bundle, with expert reports presented first (in the order served), followed by medical records organised chronologically and sub-divided by source. The index should include clear entries for each report and record set. For electronic bundles, each document should be bookmarked and the index hyperlinked. BundleCreator.co automates this formatting, producing paginated, bookmarked bundles with hyperlinked indices that meet court requirements.

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Next Steps

If you are preparing medical evidence for a personal injury claim, start by ensuring you have all relevant medical records and that your expert's report addresses every requirement of Practice Direction 35. Review the report critically — does it address causation? Does it deal with pre-existing conditions? Does it contain the mandatory statement of truth?

BundleCreator.co provides personal injury bundle templates with dedicated sections for medical evidence, expert reports, and Part 35.6 question responses. Upload your documents, organise them into the structured sections, and generate a professional, court-ready bundle with automatic pagination, indexing, and bookmarking — everything the judge needs to engage with your medical evidence efficiently and fairly.