How to Instruct an Expert Witness: A Guide for Lawyers

Last updated: 5 October 2026

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Knowing how to instruct an expert witness correctly is one of the most important skills for any asylum lawyer. A clear, well-written instruction leads to a strong report. A bad instruction leads to a weak report, wasted money, and delays. In many asylum cases, the expert report is the most powerful piece of evidence in the bundle. Therefore, getting the instruction right from the start is essential.[1]

This guide explains how to instruct an expert witness step by step. It covers what to include in your letter of instruction, common mistakes to avoid, typical timelines, and costs. Whether you are a solicitor handling asylum cases in the UK or an attorney in the US, the principles are the same. A good instruction saves time and produces a report that helps the judge make a fair decision.

What Is a Letter of Instruction?

A letter of instruction is the formal document a lawyer sends to an expert witness. It tells the expert what the case is about, what questions to answer, and what documents to read. Think of it as a brief. The expert uses this letter to understand the scope of their work. Without a clear letter of instruction, the expert cannot produce a useful report.[2]

In the UK, Practice Direction 10 of the Immigration and Asylum Chamber sets out specific rules about expert evidence. The letter of instruction must be disclosed to the tribunal and to the other party. This means the judge will see exactly what you asked the expert to do. Therefore, the letter must be professional, balanced, and focused on relevant issues. In the US, similar principles apply under the Federal Rules of Evidence, Rule 702.[3]

An expert's report is only as good as the instructions given. Vague instructions produce vague opinions. Specific, focused questions produce reports that assist the court.
Immigration Law Practitioners' Association (ILPA), Best Practice Guide on Expert Evidence, 2023

What to Include in Your Instruction

A strong letter of instruction contains several key elements. First, provide a clear summary of your client's background. This includes their nationality, ethnicity, religion, political opinion, and membership of any particular social group. Also include their gender, age, and any relevant family details. The expert needs this context to assess risk accurately.

Second, set out the specific questions you want the expert to answer. These should be clear and numbered. Good questions focus on country conditions, patterns of persecution, and the risk your client faces on return. Avoid asking too many questions. Between three and eight focused questions is usually enough. Additionally, explain which documents you are sending with the instruction. Send the client's witness statement, the refusal letter, and any relevant country reports.[4]

Third, include practical details. State the deadline for the report. Give clear format requirements, such as word count, structure, and the need for a declaration of truth. Specify the jurisdiction. A report for the UK First-tier Tribunal has different requirements than a report for a US immigration court. Finally, confirm the fee and payment arrangements.

Checklist for Your Letter of Instruction

Common Mistakes When Instructing an Expert

Many lawyers make the same mistakes when they instruct an expert witness. The most common error is being too vague. For example, asking "please provide a report on conditions in Country X" gives the expert no direction. The expert does not know which specific risks to address. As a result, the report may miss the key issues in the case.[5]

Another frequent mistake is asking too many questions. If you send 20 questions, the report becomes unfocused and expensive. The expert cannot give detailed answers to every question within a reasonable word count. Furthermore, some lawyers fail to provide enough background information. If the expert does not have the witness statement, they cannot assess the claim properly.

A particularly serious mistake is asking the expert to decide the outcome of the case. The expert's role is to provide evidence and opinion on country conditions. It is not their job to say whether asylum should be granted. That decision belongs to the judge alone.

How Long Does an Expert Report Take?

Most expert witness reports take between two and four weeks to complete. However, the timeline depends on several factors. Complex cases with multiple questions may take longer. Urgent cases can sometimes be completed in one to two weeks, but this usually costs more. Additionally, if the expert needs to interview the client, scheduling that interview adds time.

It is important to instruct the expert as early as possible. Last-minute instructions create pressure, reduce quality, and may result in the expert being unavailable. If you have a hearing date, work backwards. Allow at least four weeks before the hearing for the report, plus extra time for any follow-up questions.

Costs and Funding for Expert Witness Reports

Expert witness fees vary depending on the complexity of the case, the expert's qualifications, and the jurisdiction. In the UK, legal aid may cover expert witness fees if the case is funded by the Legal Aid Agency (LAA). However, you must obtain prior authority before instructing the expert. The LAA has set rates, which are often lower than the expert's standard fee. As a result, some experts do not accept legal aid work.[7]

In the US, there is no equivalent government funding for expert witnesses in asylum cases. Lawyers may need to cover the costs themselves or seek pro bono experts. Some organisations, such as human rights research centres and university departments, provide expert reports at reduced rates or for free. Therefore, it is worth exploring all available options before deciding that an expert report is too expensive.

How to Instruct an Expert Through The Human Rights

The Human Rights provides expert witness reports for asylum and human rights cases worldwide. To instruct an expert, visit our expert witness directory and select the country relevant to your case. You can then send a letter of instruction using the checklist in this guide. Our experts follow all requirements of Practice Direction 10 (UK) and FRE 702 (US).[8]

Every report from The Human Rights includes a full declaration of independence, a statement of truth, and a detailed methodology section. Moreover, our experts can attend hearings in person or by video link if the tribunal requires oral testimony. We accept legal aid instructions and offer competitive rates for privately funded cases. Turnaround is typically two to three weeks from the date of instruction.

Conclusion

Knowing how to instruct an expert witness properly is a fundamental skill for asylum lawyers. A clear, detailed letter of instruction leads to a report that genuinely helps the court. It saves time, reduces costs, and strengthens your client's case. Always include the client's background, specific numbered questions, relevant documents, a deadline, and format requirements. Avoid being vague, asking too many questions, or asking the expert to decide the case. Finally, instruct early. Rushed instructions produce weaker reports. With the right approach, expert evidence can make the difference between a grant and a refusal of international protection.

Free checklist. Our two-page Expert Witness Preparation Checklist for US immigration court covers screening, voir dire readiness, methodology, neutrality and the eight pitfalls judges react to.