The role of an expert witness in a commercial dispute

The role of an expert witness in a commercial dispute

Engaging an expert witness for your commercial dispute can be critical to ensure the success of your legal case. It is important to understand the role of an expert witness in a commercial dispute so you can get the best value out of their services.

An expert witness is a person who is engaged on your behalf to prepare a report which sets out their expert opinion on a subject matter of their speciality.

An expert witness is highly trained in their field, with years of experience on a specific subject matter. The purpose of an expert is to provide an objective and unbiased opinion, which they are qualified to provide, to assist the Court or a Tribunal in understanding any technical aspects of your case.


Providing an opinion

Whether a commercial dispute is being determined by a Tribunal or through Court proceedings, it is important to ascertain, as applicable, the relevant rules and codes of conduct regarding the use of expert witnesses, as well as any specific requirements regarding the format required for written reports and/or the presentation of evidence. Copies of guidelines, reporting requirements and codes of conduct, etc. should accompany the instructions provided to the expert.

An expert will prepare a report which will contain their opinion on the subject matter which you have engaged them for. Choosing a suitably qualified expert is critical with the appropriate experience in their field. If the Court finds that the expert is not qualified to provide the opinion, then the Court may not allow their report as evidence.

As part of the preparation of the expert report, you will need to provide the expert with all underlying material important to the subject matter and to provide them with targeted questions for them to answer in their report.

The expert report needs to be written so that it is helpful to the Court and includes the basis for the expert’s opinion.

The expert should also be asked to appear in Court at the time of your hearing to express their opinion. This will give the expert an opportunity to explain this opinion in further detail and the basis for it.


To be impartial

Whilst you may have engaged an expert witness to assist your legal case, the role of an expert is not to argue your case but to assist the Court without any bias. As part of this, the expert will need to form opinions based on their area of expertise and not based on what they think is right or wrong in the circumstances.

When you obtain expert evidence, the party on the other side is also likely to obtain expert evidence. The expert’s role is to assist the Court, including an understanding of any key areas of disagreement between the experts. When this happens, the Court will often encourage or require the experts to meet to discuss the subject and see if there is anything that they can agree upon. This will help the Court to understand the differences in opinions between the experts so that the Court can focus their attention on this.



Expert evidence has been identified as one of the principal sources of expense, complexity and delay in commercial disputes, there can be dire consequences and expense when an “expert” is found to be less than objective or not an expert.

Understanding the role of an expert witness can help you to understand how important it is to choose the right expert witness for your case. There are a multitude of experts available to assist but it is important to make sure that they are qualified to provide an opinion on your case and to ensure they remain objective so that the Court will allow their evidence.

If you or someone you know wants more information or needs help or advice, please contact us on 1300 149 140 or email