John Webb

I found a few years ago, when asked to act as an expert witness, that there was guidance for forensic medicine but nothing specific to internal auditors, such as myself. Having performed fraud and money laundering investigations and been a witness in criminal trials for my employer, as well as a witness at industrial tribunals, I had a little knowledge to start with but I sought guidance from my old MA tutor, Professor Paul Barnes (his specialisation in Insider Dealing and Stock Market Abuse and has resulted in numerous academic papers and books on the subject). I am a financial services specialist and we are both Certified Fraud Examiners (as well as Certified Accountants) but the advice I will now set out is not sector specific, nor is it applicable only to auditors or fraud investigators; rather it is relevant, I believe, to all accountants acting as expert witnesses.

Instruction to Act

As an experienced accountant and internal auditor, there are various reasons why the legal profession may call upon one’s services in support of litigation: -

  1. Expertise on internal control systems and how they should be audited and also what may be a reasonable response to any deficiencies found.
  2. Proven Subject Matter Expert knowledge on a matter significant to the case in question.
  3. Regulatory and/or governance knowledge in sufficient breadth and depth to be able to opine on the regulatory expectation or possibly what a reasonable management team should have built to ensure proper control thereof.

Important factors in selecting a particular person to act as an expert witness will include, previous experience of acting in this capacity, being qualified and in good standing both with the professional bodies and with the relevant regulatory body for the sector. Furthermore, the recognition of having been called upon to speak on the matter to peers and to write articles and bulletins on the subject, will be valuable. In short, to be recognised by one’s peers to be an expert.

One’s credibility and ability to assist the court will depend on knowledge and experience in the subject matter. Qualifications, experience and professional certifications should be kept up to date and recognised within the industry. Continuing professional development helps maintain expertise and credibility as an expert witness. Because regulations, industry standards and best practice change frequently, one has to prioritise keeping up to date.

It is perfectly reasonable to build on that knowledge in anticipation of an assignment by reading recent articles and regulatory pronouncements and by researching recent cases. However, this should be seen as ensuring up to date knowledge rather than simply creating that knowledge from scratch.

Relevant codes of conduct or guidelines will provide ethical as well as professional standards, for expert witnesses, including rules on independence, objectivity and transparency. It is most important to carefully consider and avoid any conflicts of interest, or any apparent conflicts of interest, that may compromise your independence or impartiality.

Experts should:

  1. Have the appropriate expertise and experience for the particular instruction;
  2. Be familiar with the general duties of an expert (and this guidance fulfils that purpose);
  3. Produce a report, deal with questions and have discussions with other experts within a reasonable time and at a cost proportionate to the matters;
  4. Be available to attend the trial, if attendance is required; and 
  5. Have no potential conflict of interest. 

Having been appointed and agreed remuneration as a party to a case, it is important to know from the outset that one is an officer of the court with a duty of care to all parties. This is clearly very different to being a mouthpiece of the party that commissioned us. The objectivity that we bring to bear as a matter of routine in auditing or accounting, is carried into the expert witness duty.

Thus, facts that may assist the other party must be explored and reported on, in the same way as those that support the case of the party that has made the appointment and is to settle the invoice. Impartiality has to be ensured and temptation to favour one party is to be firmly resisted. This way the duty to the court (and to justice) can be fulfilled.

It is likely that a client and/or their legal team may seek to bring influence to bear particularly on the specific points that underpin their reasoning but this must be countered by fairness and this understanding of duty, in order to remain objective across the board.

The role may involve assisting the court in understanding complex financial matters and providing opinions or analysis that can help resolve disputes or clarify technical issues. It is important to clearly communicate complex financial concepts and technical terminology in a manner that is easily understandable to both legal professionals and the court. Effective communication includes the use of plain language to explain opinions, methodologies and conclusions. It thus follows that reports should be clear, concise and easily understood by non-experts.

Work should be conducted with diligence and thoroughness and include a review of all relevant documentation, data and information related to the case. It will then be possible to formulate well-reasoned opinions based on a comprehensive analysis of the available evidence.

The expert should prepare thoroughly for court appearances or the submission of written reports and anticipate and address reasonable potential challenges or counterarguments to the opinions. It is wise to practice oral testimony and be prepared to defend opinions under cross-examination. Familiarisation with courtroom etiquette and procedures and maintenance of a professional and respectful demeanour while testifying, will aid the credibility of the expert witness. As will staying composed, whilst addressing questions or challenges from opposing counsel during cross-examination, not least when it appears hostile.


Guidance is available, in the form of: 

  1. Civil Justice Council Guidance for the instruction of experts in civil claims (August 2014) – click here for more detailed guidance
  2. Ministry of Justice Civil Procedure Rules 2023, Part 35 – Experts and Assessor – click here for more detailed guidance 
  3. Ministry of Justice Civil Procedure Rules 2023, Practice Direction 35 – Experts and Assessor - click here for more detailed guidance.

Sanctions may apply in the event of a failure to comply with CPR 35, the Practice Direction 35 or court orders.

Expert Analysis

The analysis is done in the context of an Expert Witness Agreement / Contract, which will include:

  1. The capacity in which the expert is to be appointed, e.g., party appointed expert or single joint expert 
  2. The services required of the expert (e.g., provision of an expert's report, answering questions in writing, attendance at meetings and attendance at court). It is important to refer to CPR 35 and PD35 compliance
  3. The commissioner of the report and their solicitor
  4. The time(s) for delivery of the report(s) 
  5. The basis of the expert’s charges, expressed as an hourly rate and an estimate of the time required, or a fixed fee for the services
  6. The expert’s disbursements, eg. necessary travelling costs
  7. Cancellation charges, eg. hours spent at time of cancellation, based on 5 above
  8. Attendance at court and fees/disbursements by the expert
  9. Time for making the payment, eg. within fourteen days of completion of these proceedings
  10. Whether fees are to be paid by a third party.

Prompt acknowledgement is needed of the Letter of Instruction sent by the solicitor (paragraph 20 of the Civil Justice Council Guidance for the instruction of experts in civil claims, provides a checklist). Experts who do not receive clear instructions should request clarification and may indicate that they are not prepared to act unless and until such clear instructions are received. Importantly, experts must neither express an opinion outside the scope of their field of expertise, nor accept any instructions to do so.

An early review of witness statements is desirable, including those of the -

I. Claimant/Applicant

II. Defendant(s)/Respondent(s)

Then a thorough review and analysis can be performed of background materials, in the context of best practice and the relevant laws, rules and regulations.


As with all report writing, one expresses an opinion based on detailed analysis and weighing of the facts. Though the report will explain the duty of the expert and that a professional opinion is being expressed (in the knowledge of the role as officer of the court), lawyers tend to prefer the reiteration of the statement “in my opinion”, throughout one’s report, whenever material statements are made.

Experts should clearly distinguish between facts and opinion and state their assumptions.

It is crucial to use plain language to explain complex financial concepts and technical terminology and ensure your opinions are precise and are understood by the court. Also use plain language to explain methodologies and conclusions and prepare a written report that outlines your opinions, the basis for those opinions and any supporting evidence or analysis. The report should be clear, concise and easily understood by lay people. As a final check, re-read it and ensure that your opinions are properly supported by the facts and can withstand sceptical scrutiny.

Maintenance of work papers that support the analysis underpinning conclusions and opinions should be retained. Questions may be received from the court and enhanced analysis requested, so the data needed to rework and thus to answer such questions, must be accessible and consistent with the original presentation.

Experts must be available to attend court and to be examined and cross examined on their reports and underlying evidence but frequently, reports are taken as read and attendance is not required. Of course, many cases are settled out of court. It is wise to draft a report in anticipation of being called upon to justify it and all that it contains or has been omitted from it.

Example of the layout of an Expert Report: -

  1. Curriculum Vitae of the Expert
  2. Instruction
  3. Summary of Material Reviewed
  4. Methodology and Scope of Report
  5. Consideration of the Main Regulations
  6. Other Considerations
  7. Analysis of the Witness Statements
  8. Conclusions
  9. Expert’s Declaration
  10. Statement of Truth (signed)


  1. Statement of the substance of all material instructions*
  2. Relevant regulatory extracts

* The mandatory statement of the substance of all material instructions should be transparent (complete and not misleading). The term “instructions” includes all material that solicitors send to experts; these should be listed, with dates. The omission from the statement of ‘off-the-record’ oral instructions is not permitted and courts may allow cross-examination on the instructions, if there are reasonable grounds to consider that the statement may be inaccurate or incomplete. 

Objectivity Challenges

Experience suggests that the greatest challenge to one’s objectivity can come from dilemmas presented by the solicitor acting on behalf of your mutual client, for example: -

  1. Challenges to certain paragraphs of the draft report.
  2. Request to insert, in too many places, words such as “in my opinion.”
  3. Irritation and possibly even anger, where you have resisted a change, which they think is important to the client’s case.
  4. Altering some of the original wording in your draft report (with or without track changes).

In any similar dilemma to those shown above, it is vital to reflect on Practice Direction for Experts and Assessors 35, paragraph 11. Always remember that experts must give opinions that are independent, regardless of any pressure and the useful ‘independence’ test that the same opinion should be given if one had been instructed by the other party to the case.

John Webb FCCA - Director, Webb Sight Consultancy Ltd