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Expert Witness Billing Advice 

April 10, 2024
Picture insert of calculator, computer and invoice.

As an expert witness, you are compensated for your time. While the contract outlines the basics of your billing rate and terms, now it is time to put it into action. 


Timeliness is key when submitting invoices. We have had experts try to “save” their invoices up and submit them all at once; if they have a retainer, wait to bill until the retainer is exhausted; or combine smaller invoices together into next month’s bill. Tempting as those options may be, always send in your invoice the month the work was performed. Why? 

  1. Attorneys need to approve your invoices, and, like everyone else, they best remember the recent past. 
  2. As carefully as you set up communications, misunderstandings still occur. Oddly enough, some of these are found in the invoices (why are there so many/so few hours?). If you turn invoices in promptly, these issues are discovered faster. 
  3. Attorneys and their clients will assume you are keeping up on your billing. If you aren’t, and instead you send them a large bill at the end, they are often taken aback and may push for discounts, etc. 


Your invoice formatting should be consistent. Most experts bill in 1/10 hour increments (though some bill in 15-minute blocks). It should be easy to read, include all the usual invoice elements (example below), and be specific enough for the attorney to understand what task you are performing without being so detailed as to be an issue for discovery (expert invoices are often discoverable). Per attorney H. Bernard Tisdale: 

Once again, you’re trying to maintain that attorney-client communication. Billing is sent to the attorney with understanding it can be addressed to the client for payment. That way you are filtering it through the attorney to protect the communication because a lot of bills are going to have time entries and descriptions of activities. All of those activities are done for the attorney providing advice. 

 An example we send to our experts, generalized slightly: 



If you want to be reimbursed for an expense, be prepared to provide copies of the receipts. Ideally, send them in with the invoice. 


If you use a retainer, be sure to show that on the invoice. The format depends on the type of retainer you have. However, as an example, if you have a $5,000 retainer to be billed against until exhausted, at the bottom of your invoice, in addition to your standard entries for time billed and expenses incurred, may also show: 

Invoice total: $2,480 

Retainer applied: $2,480 

Invoice due: $0 

Retainer applied to previous invoice(s): $500 

Retainer remaining: $2,020 

Setting Expectations for Payment 

Getting paid frequently takes longer than you think it will. As Professor Marom Bikson notes:   

Experts should know for payment you are often dealing with the lawyers, but it is coming from the client, so there is that barrier that can introduce some delays. I would pay attention to your agreements whether it is the lawyers or the client who is ultimately responsible for paying you, If it is the lawyers, and they are saying what they must pay you in 30 days, then even if the client is not paying them, they must come through. If it is a client who is responsible, they are essentially forwarding your invoice to the client. There is usually a vague understanding that it is 30 to 60 days, but you are not interfacing directly with the client. There is that extra gap.  

This gap can grow, particularly if there are questions on your invoice, or if a third party (like an insurance company) is actually footing the bill. Despite the contract terms, we find that payment takes a median of 60 days. So, half of the time it is longer than that. 

Be Flexible 

Usually this comes up during contracting, but occasionally you will know that billing needs to be set up a little differently. While hourly billing is best for most expert projects, sometimes project billing works better (for instance, independent medical exams and surveys are typically flat fees, often with the option of an hourly fee added on for conferences, etc.). Expert Michael Primeau, a digital forensics expert, tailors his billing type to the engagement:  

We typically take a project-based retainer with consulting agreements because we are working for a long period. We try to get that money approved upfront, so we are both on the same page for the scope of that project. For example, a site inspection will provide a proposal that has two days of work travel expenses. We return to the office, do more work, and then issue a report. When it comes to testifying or investigative work or analysis work that is billed hourly to put together a package. Then have some sort of retainer at minimum upfront. When you are working on a court-appointed case those rules are completely different. They have a limitation as to what they can do. For an hourly rate, when you are working on a civil investigation, maybe the insurance company does not want to cover the fees or whatever. There are different steps we take with that. It depends on the case, but for the most part, if we are providing a service like an enhancement that is based on an hourly amount, we try to get that approved upfront because some agencies take several months to provide funds. If I am working for someone like law enforcement or where they may have a net 60-day [turnaround on invoices], we try to be flexible with that as long as we agree on the money up-front. If we agree, we will proceed. Packages are used when we consult for large investigations.

When an engagement involves both a fixed fee component and hourly billings, be very specific in your contract and invoices for which work is covered in the project rate and which is billed hourly. 

Be Mindful of Estimates 

Attorneys frequently try to manage billing expectations for their clients, and it is typical for attorneys to ask for an estimate. We strongly recommend you give these estimates in hours instead of dollar figures and list out what is included in the estimate. Using hours causes you to really think through how long it may take, and (if you are working via a company like Round Table Group) you don’t have to worry about factoring in their fees. Also, remember your estimate. Even if you think it’s just a rough estimate based on limited information during a 10-minute phone call, the attorney (and their client) will likely not view it that way. Setting expectations in advance can help mitigate this. 

If you think you might exceed the estimate (even if that estimate was an informal one given early in the engagement process), notify the attorney. Frequently they will be o.k. with it if they know it is happening and why – but just in case, notify them before you exceed the estimated hours. 

Moreover, it is a best practice to keep track on the invoices of how you are doing against the estimate (show the total estimated hours, and the number billed so far). That helps keep everyone on the same page and reiterates what is included in the estimate. 

Pay Attention to Pencils Down 

Attorneys and their clients will not pay for any time after they have informed you that a matter is closed (be that settlement, judgement, or some other outcome). As Dr. Chuck Easttom notes: “[Attorneys] are usually proactive. If the case stops, I usually get a pretty urgent e-mail saying to put your pen down and stop adding billable hours to the fee because we are done.” 

A Client Questioned My Bill! 

A surprising amount of friction occurs over billing, so be careful to get your end right. Present your invoices in a clear and timely manner, in reasonable but not excessive detail. Understand when following up, that it typically takes time for expert invoices to be paid, and plan accordingly. When a client questions your bill, first be inquisitive. Work to understand if there was a miscommunication about the scope of work or some other issue. Once you’ve gathered the information, determine what is the appropriate response. Do they have a point? Should you provide a discount or hold firm? Then, in a pleasant, thoughtful manner, respond to the attorney with your solution and justification. 

Billing on a matter doesn’t have to be stressful. The trick is effective communication with the attorney throughout the engagement, clear expectations, clear and timely invoicing, and clear, calm responses to questions. 

If you are interested in being considered for expert witness gigs, sign up with Round Table Group. For 30 years, we have helped litigators locate, evaluate, and employ the best and most qualified expert witnesses. Contact us at 202-908-4500 for more information or sign up now! 

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