By Jordan Mitchell, March 10, 2026

AV Law Site

Travel billing remains one of the most debated aspects of an expert witness’s invoice, provoking conflicts between witnesses and retaining attorneys. The central issue typically revolves around how much travel time should be compensated for the time spent traveling to depositions or trials compared to the actual testimony time delivered. Witnesses often find themselves in a tug-of-war with attorneys, who may believe they should only pay for the actual time spent testifying. In contrast, the expert witness expects proper compensation for the entire journey, which can be a significant part of their professional commitment.

This article aims to clarify the different models for billing travel time, outline how to handle expense reimbursement, and provide specific engagement letter language that eliminates ambiguity, thereby preventing future disputes over travel billing.

The Three Travel Billing Models

Expert witnesses typically adopt one of three standard models for billing travel time. Each approach has its own advantages and disadvantages, making it essential for experts to select the model that best aligns with their practice and the expectations of the retaining attorney.

Model 1: Half Rate (Most Common)

Charging travel time at 50% of the normal hourly rate is the most widely accepted practice among expert witnesses. This method is frequently recommended by organizations such as SEAK and mirrored in various fee surveys. The rationale behind this approach is straightforward: While travel requires time and prevents the expert from engaging in other work, the actual level of professional input required is typically lower than that of providing testimony or preparing reports.

For instance, if your standard consulting rate is $400/hour, billing travel at $200/hour allows for meaningful compensation without making the invoice appear inflated. A full day of travel (eight hours) at this half-rate would generate $1,600, which presents a reasonable charge on an invoice. Accordingly, itemizing travel separately at a half-rate helps maintain overall clarity for the retaining lawyer.

The half-rate model is considered the safest default since it aligns with common practices recognized by courts. Opposing counsel seldom challenges this approach, making it an effective strategy for most expert witnesses.

Model 2: Full Rate

Some experts opt to charge their full hourly rate for travel, particularly when the travel itself displaces other billable work or is significant contextually. For example, surgeons who cancel clinics, engineers who leave active project sites, and financial advisors who forgo client meetings can justify billing their full rates due to the direct opportunity costs involved.

However, billing travel at a full rate necessitates clear justification, especially if challenged by opposing counsel. If you charge, say, $500/hour for travel, you must articulate why your travel time should command the same rate as your professional analytical work.

Full-rate billing is defensible especially under circumstances such as reviewing case material while in transit (noting that this time should be logged as a separate file review), when travel interferes with scheduled patient care or client engagements, or when your engagement letter explicitly states travel will be billed at the full rate, with the retaining attorney’s acknowledgment.

Model 3: Flat Fee

A growing number of experts are adopting flat fees for travel, meaning they charge a fixed amount per travel day regardless of distance or duration. Common structures might include $1,500 for any travel day or $2,000 for travel that necessitates an overnight stay. Alternatively, some use tiered rates, such as $750 for travel under 200 miles, $1,500 for distances between 200-500 miles, and $2,500 for journeys surpassing 500 miles.

Flat fees simplify invoicing and streamline budgeting for attorneys, as it removes the need to track hours, allowing for a predictable cost. However, this method can be inflexible: Charge a flat $1,500 for a 90-minute drive, and you may overpay, while a full day of interconnections may remain underpaid.

Comparing the Three Models

Portal-to-Portal vs. City-to-City

Defining what constitutes “travel time” is critical regardless of the model you adopt. The two prevalent methods are portal-to-portal and city-to-city billing, both of which can yield significantly different billable hours.

Portal-to-Portal

Portal-to-portal billing refers to door-to-door billing practices—the clock starts when you depart your home or office and stops upon arrival at your destination, whether that be a hotel or a courthouse. This method includes the entirety of the trip: driving to the airport, waiting at the gate, flight time, layovers, and ground transportation. Thus, a journey involving a 2.5-hour flight may in total generate 6-7 hours of billable travel time.

Most experts lean toward portal-to-portal billing due to its representation of the actual time commitment. However, confusion arises when experts live far from major airports; for example, if you live 90 minutes away from the nearest airport, the travel time may result in disputes from attorneys who question its validity.

City-to-City

In contrast, city-to-city billing counts only the time from one metropolitan area to another—essentially the flight time plus reasonable ground transportation at each end. Commute times to the airport and wait times at security do not factor into this billing method.

While city-to-city billing may seem less favorable for the expert witness, it can be useful when budget-conscious retaining attorneys prefer to keep expenses low. Some experts adopt the city-to-city approach for air travel while choosing portal-to-portal for driving assignments.

The key takeaway: Whichever convention you decide upon, clarity in your engagement letter is paramount. Vague terms lead to the majority of travel billing disputes.

Expense Reimbursement

It’s crucial to understand that billing travel time is distinct from claiming expense reimbursement. Expenses are the actual costs incurred—airfare, hotel, rental cars, and meals—which are billed at cost and passed through to the retaining attorney. Clearly outline reimbursement terms for every category within your engagement letter.

Airfare

The common practice involves billing for economy class on flights under four hours and utilizing business class for longer flights or red-eye trips preceding testimony days. Many engagement letters stipulate that airfare must be the “lowest available coach fare booked at least 14 days in advance” to avert disputes concerning last-minute premium bookings. Always retain confirmation emails and receipts for all flights.

Hotel

Generally, reasonable hotel expenses are reimbursable. “Reasonable” typically implies mid-tier accommodations, such as Marriott, Hilton, or Hyatt. If depositions occur in costly areas like Manhattan or San Francisco, it’s understood that higher nightly rates apply. Some experts opt to cap their nightly hotel rates in engagement letters ($250/night, with adjustments for pricier cities) to manage expectations.

Meals and Per Diem

Experts commonly face two options: billing actual meal costs with receipts or opting for a per diem aligned with IRS rates. The per diem method simplifies the process—there’s no need to collect receipts, and disputes are minimized regarding the “reasonableness” of specific meal expenses. Current IRS per diem rates vary by city, normally falling between $59 and $79, escalating in high-cost areas like New York City or San Francisco. You can find current rates in IRS Publication 1542 or on GSA.gov.

Mileage

When traveling to a deposition or trial, it’s advisable to bill mileage at the current IRS standard mileage rate (72.5 cents per mile as of 2026, increased from 70 cents in 2025). This is a universally accepted standard that attorneys typically do not question. Be sure to include the trip’s origin, destination, and total mileage on your invoice. For trips exceeding 200 miles one-way, experts frequently find flying more economical than driving, particularly when considering the combination of travel time and mileage reimbursements.

Other Expenses

Reimbursable expenses also cover rental cars, parking, tolls, and ground transportation (rideshare or taxi) billed at actual cost with receipts. The per diem may include minor expenses like airport Wi-Fi, baggage fees, and printing costs. However, avoid billing for personal items like minibar charges or in-room movies—although this may seem obvious, such charges have been contested in expense disputes.

When to Charge Full Rate for Travel

There are specific scenarios where full-rate billing for travel is not justifiable but expected:

• Same-day return trips for testimony: When flying out early for a deposition and returning the same day means sacrificing an entire working day, billing the testimony hours at full rate while charging travel time+waiting at your travel rate is standard practice.
• Multi-day trial appearances: When required in court over consecutive days, experts generally bill each day at their full testimony rate, while surrounding travel days are charged at the travel rate.
• Working during transit: If using travel time to review case materials or prepare testimony, log this time separately at your applicable activity rate rather than your travel rate, as the latter should encompass only non-working transit periods.
• Last-minute travel: When requested to travel on short notice (under 72 hours), charging a premium is justified. It’s beneficial to have an engagement letter that includes a clause: “Travel arranged with less than 72 hours’ notice will be billed at the full hourly rate.”

Engagement Letter Language for Travel Terms

In drafting your engagement letter, specifically address travel billing to prevent disputes thoroughly. Here is a template covering the essential elements:

Travel Time: Travel time shall be billed at 50% of my standard hourly rate, calculated portal-to-portal (from departure from my office or residence to arrival at the destination, and return). Travel time during which I am performing case-related work (document review, report preparation, testimony preparation) shall be billed at the applicable activity rate.

Travel Expenses: Reasonable travel expenses shall be reimbursed at cost, including: (a) airfare at coach/economy class for flights under 4 hours, business class for flights over 4 hours; (b) hotel at reasonable business-class rates; (c) meals at the applicable IRS per diem rate; (d) ground transportation (rental car, taxi, rideshare) at cost; (e) mileage at the current IRS standard mileage rate for personal vehicle use. Receipts will be provided for all expenses except per diem meals.

Travel Arrangements: Unless otherwise agreed, I will make my own travel arrangements. Travel booked with less than 72 hours’ notice may be subject to premium fares, which will be billed at cost.

This language ensures that the terms are precise enough to mitigate disputes while retaining the flexibility to accommodate various travel scenarios. Feel free to adjust the percentage rates, airfare class thresholds, or per diem structures to match your practice needs.

Travel Billing Disputes

Even with unambiguous terms in your engagement letter, travel billing disputes can still arise. The most frequent challenges include:

• “You billed 8 hours of travel for a 2-hour flight.” This is usually due to confusion between portal-to-portal and flight-time-only billing methods. Clearly outline your billing approach in the engagement letter to alleviate potential confusion.
• “Business class was not authorized.” If your engagement letter permits business class for flights over a certain duration, reference that clause. Absence of specific airfare class guidelines may weaken your position.
• “Your hotel was too expensive.” Present the receipt demonstrating that the rate corresponds with mid-tier business hotels in the city. If your engagement letter stipulates a cap on nightly rates, show proof of compliance.
• “We should not pay for travel when the deposition was canceled.” If you had already traveled or incurred non-refundable expenses prior to cancellation, your engagement letter should address non-refundable costs to protect you.

Tracking Travel Time Alongside Case Work

Effectively tracking travel time presents a practical challenge, as travel time must be logged distinctly from any case work accomplished during that time. For example, if you spend two hours reviewing documents while en route, you need to separate your time logs into two entries: one for file review at your applicable hourly rate and another for travel (excluding the working time) at your travel rate. The best time-tracking tools for expert witnesses facilitate this split automatically, freeing you from reconstructing absent-minded logs later.

ExpertPractice is one such tool that includes travel as a built-in activity type with its own designated rate in your per-case structure. By selecting the activity type, your travel rate auto-fills, negating the need for mental calculation, while ensuring you avoid any inadvertent mischarges by billing travel at your testimony rate.

Frequently Asked Questions

Is expert witness travel time billed at 50% of the hourly rate?

Billing travel time at 50% of the standard hourly rate is indeed the predominant practice among expert witnesses and aligns with most published fee surveys; however, it’s not a rigid requirement. Some experts may bill their travel at full rates if displacing other billable work, while others might employ a flat daily fee. Be explicit about your chosen model to prevent misunderstandings.

For those looking to shape their practices around efficient travel billing, integrating systems such as ExpertPractice can materially enhance the management of travel time and billing alongside actual case work.

For more in-depth resources, including knowledge on AV Law Site’s services, experts can review material that enhances their understanding of effective billing practices.

Disclaimer: This content is for informational purposes only and does not constitute legal, financial, or professional advice. Rates, benchmarks, and practices vary by jurisdiction, specialty, and individual circumstances. Consult with a qualified attorney or accountant before making decisions about your practice.