Expert Witness Agreement: What It Is and Why You Need One

This guide will provide a practical overview of expert witness engagement—what they include, why they are necessary, and how they help safeguard legal professionals,  experts and clients, and help ensure the expert complies with their obligations to the court. Whether you are a solicitor, barrister, or expert witness yourself, understanding this agreement is key to a clear and professional working relationship.

What Is an Expert Witness Agreement?

An expert witness agreement is a legally binding contract between an expert witness and the instructing party—typically a solicitor or law firm, or client. It defines the terms under which the expert will provide their professional opinion in a legal case.

The primary purpose of this agreement is to establish clear expectations, responsibilities, and conditions of engagement. It ensures that all parties (and any other entities which may not be a party but may have an interest in the engagement – such as the court or the other side) understand the scope of the expert’s role, the nature of their work, fees, deadlines, confidentiality obligations, and compliance with relevant legal and procedural rules.

Several key stakeholders are involved in expert witness engagements, including:

• Expert witnesses – professionals providing independent, specialised knowledge.
• Solicitors and barristers – legal representatives who instruct and rely on experts to support their client’s case.
• Courts and tribunals – which expect expert witnesses to provide impartial and reliable evidence to help inform their understanding of a complex issue.
• Clients – the party who engages the expert and who are involved in the proceeding.
• Indirectly, opposing experts as they will be reading, analysing and critiquing the evidence of the expert engaged as part of that engagement.

A well-drafted expert witness agreement helps protect all parties by preventing disputes, ensuring legal compliance, maintaining professional integrity throughout the case, and mitigating challenges to an expert’s evidence to the court.

Key Elements of an Expert Witness Agreement

A well-drafted expert witness agreement provides clarity, professionalism, and legal and ethical protection for both the expert and the instructing party. To ensure a smooth and structured engagement, the agreement should include the following key elements:

Identification of Stakeholders

The agreement should clearly state:

• The name, qualifications, and contact details of the expert witness. Simply copy these details from your expert witness CV.
• The instructing party’s details (e.g., solicitor, law firm, or client).
• Reference to the Court (or arbitration etc), and the specific proceedings 
• Any other relevant entities involved in the engagement.

This ensures there is no ambiguity about who is entering into the contract.

Scope of Work

Defining the scope of work prevents misunderstandings about the expert’s role, or challenges to evidence based on it. This section should specify:

• The specific points or questions on which expert evidence is required.
• The exact nature of the expert’s deliverables, such as preparing reports, conclaves and giving testimony.
• Whether the expert is required to provide evidence in response to another expert.
• What the expert is not required to do, ensuring there are no unrealistic expectations.
• Key deadlines and deliverables, including expert witness report submission dates and court appearances. 

A well-defined scope protects the instructing party and the expert and ensures that expectations are aligned and reasonable.

Fee Structure and Expenses

Financial transparency is crucial to preventing disputes.

The expert witness retainer agreement should clearly define the expert’s fee structure, including hourly or daily rates, fixed fees, or retainers. It should specify invoicing terms, payment deadlines, and acceptable methods, as well as outline expense reimbursements for travel, accommodation, or materials. 

Provisions for cancellation or late payment fees help protect the expert from financial losses. Clear financial terms ensure smooth transactions and timely payments.

Note that any fee structure should NOT be conditional on the outcome of the case – to do so would give rise to significant ethical issues for the expert.

Confidentiality and Data Protection Clause

Expert witnesses handle sensitive legal and personal data, making confidentiality crucial. The agreement should include:

• A confidentiality clause, restricting the disclosure of case information to third parties.
• Compliance with relevant data protection laws, ensuring secure handling of client data and other confidential information (such as that provided by the Court or other side).
• Where possible, a commitment to maintaining legal privilege, preventing unauthorised sharing of privileged communications. 

This confidentiality agreement for expert witnesses protects both the expert and the client from  confidentiality or disclosure issues arising from the engagement. 

Compliance with Legal and Ethical Obligations

Expert witnesses must comply with legal and ethical rules governing their engagement. The agreement should confirm that the expert:

• Understands and agrees to follow the relevant expert witness rules or code of conduct.
• Is bound by the relevant procedural rules.
• Has a primary obligation to the Court (or Tribunal) and will act independently and impartially, prioritising duty to the court over the instructing party or any other entity.
• Will adhere to professional standards, ensuring their opinion is based on expertise, skill and experience.

This section reinforces credibility and ensures the expert’s evidence is admissible.  Moreover, a failure to include such a section may result in tension in relation to the expert’s engagement with their client, and potentially difficult cross examination by an opposing counsel.

Termination Clause

Both parties should have the right to terminate the agreement under specific conditions. The clause should define acceptable grounds for termination, such as contract breaches, conflicts of interest, or non-payment. 

It should specify the required notice period and address financial implications, including outstanding payments or refunds. A well-defined termination clause ensures a clear exit strategy if the engagement becomes unworkable.

Governing Law and Jurisdiction

In case of disputes, the agreement should specify:

• Which state’s laws will govern the contract.
• The jurisdiction where disputes will be resolved (e.g., courts of New South Wales).

This ensures that both parties know where and how legal matters will be handled.

Common Mistakes to Avoid

A well-drafted expert witness agreement is essential for a smooth and professional engagement. However, many experts overlook key details, leading to unnecessary disputes and complications. Here are some of the most common mistakes to avoid:

Not Having a Written Agreement in Place

Relying on verbal agreements or informal email exchanges can lead to misunderstandings and legal risks. Further, a written agreement is essential if an expert is to be providing evidence to a court.  A written expert witness agreement ensures that all terms are clear, enforceable, and legally binding. Without one, disagreements over fees, scope of work, or confidentiality can quickly escalate, and an expert’s evidence in a court will be open to challenge.

Failing to Agree the Engagement Prior to Starting Work

Your Expert witness engagement should be negotiated and agreed before starting work as an expert.  From a commercial perspective this makes sense, as any work done prior to this will not be governed by an agreement.  Additionally, courts will expect such an agreement to be in place prior to your engagement commencing – after all, such an agreement regulates how you perform your overriding duty to the Court.

Vague Fee Arrangements Leading to Disputes

Unclear financial terms in an expert witness retainer agreement can result in payment delays or disputes. To prevent this:

• Clearly outline fee structures (hourly/daily rates, retainer fees, or fixed fees per step or stage).
• Specify payment terms, including invoice deadlines and late payment penalties.
• Address cancellation fees if the case is settled or postponed.
• Potentially provide costings for possible interim or interlocutory steps or applications or assistance in settlement negotiations which may involve more (or less) work as a result.

Without a well-defined fee arrangement, experts risk unpaid work, and legal teams may face unexpected costs.

Failure to Define the Instructions and Scope of Work Clearly

An ambiguous scope of work can lead to unrealistic expectations, excessive demands, scope creep and/or disputes. The agreement should:

• Specify the expert’s role – whether providing expert witness reports, testimony, or consultation only.
• Outline deliverables and deadlines to avoid last-minute pressures.
• Clarify what is not included, preventing scope creep.

A clear scope of work protects both the expert and the instructing party from unnecessary conflicts.

Ignoring Confidentiality and Data Protection Obligations

Expert witnesses frequently handle sensitive legal and personal information, making confidentiality essential. 

A well-drafted agreement should require compliance with privacy and data protection laws, emphasise legal privilege to prevent unauthorised disclosure, and establish secure methods for storing and sharing information. 

Failing to address these obligations can result in confidentiality breaches, reputational harm, and legal liability for both the expert and the instructing party.

Not Addressing Liability or Insurance Coverage

If an expert’s opinion is challenged or found to be flawed, they could face professional or legal consequences. The agreement should:

• Define the expert’s liability in case of errors or omissions.
• Require the expert to maintain professional indemnity insurance to cover potential claims.

Without clear liability and insurance provisions, both parties may face financial and reputational risks.

Avoiding these common mistakes ensures that an expert witness agreement is effective, legally compliant, and protects both the expert and the instructing party.

How to Draft an Expert Witness Agreement

A well-drafted expert witness agreement ensures clarity, professionalism, and legal protection for both the expert and the instructing party. To create an effective agreement, follow these key steps:

1. Use a Professional Template or Seek Legal Advice

Starting with a professional template can save time and ensure that the agreement includes all essential elements. However, generic templates or templates for general engagements by the expert (i.e. for “regular” work and not as an expert) may not cover the legal or procedural requirements critical to an expert engagement, so it’s advisable to:

• Use a template designed for expert witness engagements.
• Seek legal advice to ensure compliance with relevant laws and court rules.  Note that any such advice should be from a separate lawyer, not your instructing solicitors.
• Customise the agreement to reflect the specific needs of the case.

A properly structured agreement reduces the risk of disputes and ensures legal enforceability.

2. Ensure It Is Tailored to the Specific Case and Jurisdiction

Legal and procedural requirements differ by jurisdiction, so the agreement must specify the applicable laws and court rules, such as the UCPR 2005 in New South Wales (including Schedule 7 which contains the Expert Witness Code of Conduct). It should be tailored to the type of case, whether civil, criminal, family, or commercial litigation, and include any specific terms required by the instructing party or court. 

A well-structured agreement ensures compliance with legal standards and professional expectations.

3. Review and Update Your Standard Terms Regularly to Reflect Changes in Legal Requirements

Legal frameworks and court rules evolve over time. To maintain compliance and relevance, the agreement should be:

• Reviewed periodically to reflect updates in expert witness regulations.
• Updated when new legal precedents or procedural changes occur.
• Adjusted based on feedback from previous cases to improve clarity and effectiveness.

A regularly updated agreement ensures that both the expert and the instructing party remain protected under current legal standards and obligations.

Drafting an expert witness agreement requires careful planning and attention to detail. By using a professional template, customising it for the case and jurisdiction, and keeping it up to date, legal professionals and expert witnesses can ensure a clear, compliant, and effective working relationship.

Expert Witness Agreement Template (Example Format)

Below is an expert witness agreement template, outlining the key sections and best practices discussed in this guide. To receive a sample of an expert witness agreement, please fill out the form below:

How to Negotiate an Expert Witness Agreement

Negotiating an expert witness fee agreement is a crucial step in ensuring a fair, professional, and legally sound engagement. Both the expert and the instructing party should aim for an agreement that is clear, enforceable, and mutually beneficial. Here’s how to approach the negotiation process effectively:

Understanding Your Worth – Setting Fair Compensation Based on Expertise

Expert witnesses should be compensated fairly based on their qualifications, experience, and the complexity of the case. To ensure reasonable fees:

• Research industry standards for expert witness fees in your field and jurisdiction.
• Consider factors such as time commitment, case complexity, and court appearances.
• Define whether the fees are hourly, daily, or a fixed rate, and include provisions for additional work if required.
• Be prepared to justify your rates with examples of past cases or professional credentials.
• See what fees other experts charge in the field.

A good yardstick for your expert witness hourly rates would be use your hourly rate for non-expert witness work.  You can also compare your rate against those charged by the solicitor or barrister – you might find that your rate is very reasonable compared to those charged by the legal team!

Setting clear compensation terms helps avoid disputes and ensures the expert is paid appropriately for their expertise.

Clarifying Expectations – Agreeing on Deadlines, Deliverables, and Scope

To avoid misunderstandings, both parties should agree on the scope of work before finalising the agreement. This should clearly define the expert’s role, whether providing written reports, oral testimony, or consulting services. 

It should set deadlines for report submission, court appearances, and availability while outlining any limitations to prevent unrealistic expectations or excessive demands.  Be sure to discuss special provisions in the event additional work is required (or not required) such as for specific applications or topics. Establishing these terms upfront ensures a smooth and efficient working relationship.

Handling Dispute Resolution – Addressing Issues Proactively

Disputes may arise over fees, confidentiality, or the expert’s role. To mitigate risks, the agreement should include:

• A dispute resolution clause outlining how disagreements will be handled (e.g., mediation, arbitration, or legal action).
• A clear process for addressing late payments or unpaid invoices.
• Confidentiality breach consequences, ensuring both parties understand their responsibilities under privacy and legal privilege rules.

By having a structured dispute resolution process, both parties can avoid unnecessary legal conflicts.

Negotiation Tips – Ensuring a Balanced and Enforceable Agreement

Successful negotiation requires a professional and strategic approach. Consider these tips:

• Be clear about your non-negotiables – Decide which terms (e.g., fees, deadlines, or confidentiality clauses) you are firm on.
• Be open to reasonable compromises – Flexibility can lead to a more cooperative agreement.
• Get everything in writing – Verbal agreements can lead to misunderstandings, so ensure all negotiated terms are documented.
• Seek legal advice if necessary – If complex clauses or jurisdictional issues arise, consulting a legal professional can help protect your interests.

A well-negotiated agreement ensures that both the expert and the instructing party are on the same page, reducing the risk of conflicts later.

Updates and Changes: When to Review Your Agreement

An expert witness agreement is not a one-time document—it should be reviewed and updated as circumstances change. Regular revisions ensure that the agreement remains legally compliant, professionally relevant, and aligned with the expectations of both parties.

When Should Experts or Solicitors Revise Their Agreement?

Expert witnesses and solicitors should regularly review their agreements to ensure they remain relevant and effective. This is particularly important at the start of each new engagement to tailor terms to the specific case, when disputes arise to clarify any issues, and periodically to keep terms aligned with current legal and professional standards. 

When working in a new jurisdiction or under a different legal framework, the agreement should be updated to comply with applicable court rules in that new jurisdiction.

How Changes in Laws, Professional Guidelines, or Case Scope May Require Updates

The legal landscape and professional responsibilities of expert witnesses can evolve over time. Key triggers for an agreement update include:

• Changes in court rules or procedural laws – For example, updates to NSW Uniform Civil Procedure Rules (UCPR 2005).
• New data protection regulations – Ensuring continued compliance with privacy and client confidentiality rules.
• Shifts in case scope – If the expert is asked to provide additional services (e.g., testifying instead of only providing written reports), the agreement should reflect this.
• Professional practice and standards updates – Changes in industry standards, accreditation requirements, or best practices for expert witnesses.

Ensuring Ongoing Compliance with Procedure Rules, Privacy Laws, or Other Regulations

To maintain professionalism and legal integrity, expert witness agreements must always align with current regulations. A robust review process should:

• Ensure compliance with the relevant procedural rules and expert witness code of conduct in that jurisdiction – Confirming the expert’s duty to the court remains clear.
• Check privacy and data protection terms – Updating clauses on confidentiality, data handling, and security measures.
• Reassess indemnity and liability clauses – Ensuring the expert has adequate professional insurance to cover potential claims.

Regularly reviewing and updating an expert witness agreement is essential for maintaining clarity, compliance, and professional integrity. By staying ahead of legal changes, refining contractual terms, and ensuring ongoing alignment with case requirements, both expert witnesses and legal professionals can minimise risks and uphold best practices in their engagements.

Conclusion

A clear, well-drafted expert witness agreement is essential for ensuring professionalism, legal compliance, and a smooth working relationship between the expert and the instructing party. By defining key terms such as scope of work, fees, confidentiality, and legal obligations, the agreement helps prevent misunderstandings, disputes, and potential legal risks.

Having a structured agreement protects both the expert and the solicitor by setting clear expectations and ensuring compliance with relevant laws and court rules, such as the civil procedure rules and privacy law. Without one, experts risk unpaid fees, legal complications, and reputational damage, while instructing parties may face issues with expert reliability and admissibility of evidence.

To avoid financial and legal risks, professionals should always use a formal expert witness agreement tailored to the specific case and jurisdiction. A well-prepared agreement not only strengthens the expert’s credibility but also reinforces trust and professionalism in legal proceedings.

If you want to enhance your understanding of expert witness roles and best practices, Loquitur provides expert witness training, both online and in person. Their courses cover key legal principles, compliance requirements, and practical skills to help expert witnesses succeed in their role. 

For more details, visit Loquitur’s training programme and ensure you’re fully prepared for expert witness engagements.