I've been contacted on LinkedIn by a lawyer and his clients. They asked me if I would be interested in reviewing a piece of source code and answer specific questions they have about it such as whether it performs this or that function, how long it would typically take to write such code, etc.

I'm qualified to review the code and provide detailed, argumented answers to their questions, and I would be delighted to help them. However it would be my first case as an expert witness and I'm unsure about the quote I should give them.

To be more precise, I need to provide a quote for an "initial review" which they estimate would take around 8-10 hours (which I think is entirely reasonable even if I may adjust this slightly). I would also need to travel (international, 4-hour flight) to attend a cross examination that they estimate would take 2 to 3 hours (but at least 36 hours in total if travel and accomodation is accounted for).

Even though I did consulting for a few years a long time ago, I'm no longer self-employed. I'm a principal engineer in a software company in an entirely unrelated line of business. However I have a strong presence in the open source community and it's as an open source project leader and software author that I would testify (in my free time).

As an established software author in France with around 20 years of experience in the field related to the code I'm being asked to review, what would be a reasonable hourly rate? Beside the 8-10 hours for the initial review and the 2-3 hours for the cross examination, what else should I bill? Should I simply increase the hourly rate to account for the 36 hours of travel time, or would they typically pay travel (and related) expenses?

Thanks for all the help in this new exciting adventure. Quick answers are appreciated since the timing is rather tight on this one.

  • US but may be helpful: seak.com/expert-witness-fee-study
    – Scott
    Feb 11, 2018 at 20:55
  • User resides in France. In the future, you can submit an edit to the question, and other users can vote to allow it in or not
    – Canadian Luke
    Feb 12, 2018 at 18:04
  • It is your civil responsibility to stay withing the boundaries of the law and pay your taxes. As long as you pay tax on your extra income, the state has nothing to say. Are you allowed to invoice companies without being firstly registered? This you have to check by yourself. In terms of money, you should be paid at least 600 Euro/day + Travel/Accommodation. Feb 15, 2018 at 15:39

1 Answer 1


What I would do:

As a rule ob thumb I would about triple the current gross hourly amount you are making under your normal employment. Adjust to how much you want or not want to do this.

Then bill all hours you spent, incl researching and administrative. For on-site appointments bill a whole-days rate (8 hours). Travel expenses (Flight + Hotel) should be paid by contracting party. Add a generous daily allowance for additional expense (food etc.)

Some additional questions to ask:

  • Are you allowed to take compensation for this under your current employment contract?
  • Can you in any way be held liable for the findings of your review? Do you need insurance for this?
  • Do you need special visa etc. when you get compensated for your trip?
  • How to invoice, taxes involved?

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct.

Not the answer you're looking for? Browse other questions tagged or ask your own question.