Mileage Reimbursement

What is Mileage Reimbursement?

Mileage reimbursement is compensation an employer pays to employees who use personal vehicles for business purposes, covering fuel, vehicle depreciation, and wear and tear. Rather than requiring employees to collect gas receipts, companies calculate the payment by multiplying business miles driven by a set rate per mile.

Most companies benchmark their rate against the IRS standard mileage rate, which the Internal Revenue Service updates annually based on fixed and variable vehicle operating costs. The 2026 IRS business rate is 72.5 cents per mile [1]. Reimbursing at or below this rate under an IRS-compliant accountable plan keeps payments non-taxable for employees and deductible for the employer.

Mileage reimbursement is one component of a broader expense report process, alongside per diem allowances, corporate card transactions, and out-of-pocket receipted expenses.

How Does Mileage Reimbursement Work?

The mechanics are straightforward: an employee drives a personal vehicle for a business trip, records the miles excluding commutes, and submits a mileage log for reimbursement. The employer multiplies the miles by the company's rate and pays the employee directly or includes the amount in the next paycheck.

For a field sales representative who drives 400 business miles in a month, the reimbursement at the 2026 IRS rate works out to $290. That amount represents real operating costs the employee deserves to recover without collecting a stack of gas receipts.

Finance teams can use Navan's mileage reimbursement calculator to estimate annual program costs by headcount, average monthly miles, and rate, giving them a baseline for budgeting before policy decisions are finalized.

IRS Standard Rate vs. Actual Expense Method

Two calculation methods exist for business vehicle costs. The standard mileage rate method uses a flat per-mile rate that covers fuel, insurance, registration, and depreciation in a single number. The actual expense method tracks every vehicle cost individually: gas, oil changes, insurance premiums, and repairs.

For most companies, the standard mileage rate is simpler to administer and easier for employees to document accurately. The actual expense method can be more precise for high-volume drivers in markets with elevated fuel costs, but it requires more granular recordkeeping from employees who may already find expense reporting time-consuming.

When Is Mileage Reimbursement Taxable?

Mileage reimbursement is not taxable when paid under an IRS accountable plan with three conditions met [1]:

• Business connection: The trip must serve a genuine business purpose. Commuting from home to a regular office does not qualify.
• Substantiation: Employees must record the date, starting point, destination, business purpose, and miles for each trip.
• Return of excess: Any reimbursement exceeding substantiated amounts must be returned to the employer within a reasonable time.

What Mileage Qualifies for Reimbursement?

Business miles cover driving that directly serves employer business: traveling between office locations, driving to client or customer sites, attending off-site meetings or conferences, and picking up supplies for the company. Regular commuting from home to a fixed workplace does not qualify under IRS rules.

The distinction matters when employees mix commuting and business driving in a single trip. A procurement manager who drives from the office to a supplier warehouse and back can claim those miles; the morning drive from home to that same office cannot be included in the same submission.

Best Practices for Mileage Reimbursement Programs

Finance teams with high-performing mileage programs follow five consistent practices.

Set a rate and publish it clearly. Document the per-mile rate in your travel and expense (T&E) policy alongside step-by-step instructions for calculating business miles and submitting logs. Ambiguity about what qualifies as a business trip is the primary source of non-compliance and exception requests.

Capture at the point of travel. Employees who log mileage immediately after a trip produce more accurate records than those who reconstruct routes at month-end from memory. A Forrester TEI study found organizations using Navan achieved an 80% reduction in expense report processing time by moving documentation to the point of transaction [3].

Separate commute from business miles. The most common mileage audit finding is employees including commuting miles in business reimbursement claims. Clear policy guidance, paired with prompts asking employees to confirm trip purpose during submission, catches this error before the claim reaches finance review.

Match submissions to calendars. Cross-referencing mileage logs against meeting invitations and CRM records surfaces route inconsistencies that manual review misses. Navan Expense automates this cross-check by connecting expense submissions to calendar and booking data.

Review by cost center. Segmenting mileage spend by team, region, or project identifies outliers worth investigating. A field sales team averaging 1,200 miles per month per representative is expected; the same mileage pattern in a finance or HR team that rarely needs off-site travel merits clarification.

A Practical Scenario: Regional Sales Rep Mileage Program

A regional sales manager at a mid-sized manufacturing company covers a four-state territory. She drives her personal vehicle approximately 1,500 miles a month visiting prospects, attending trade shows, and conducting quarterly business reviews at customer sites.

At the 2026 IRS rate of 72.5 cents per mile, her monthly reimbursement totals $1,087.50, or roughly $13,050 annually. That is a meaningful component of her total compensation that affects both job satisfaction and whether she uses a personal vehicle rather than expensing a rental car. When the reimbursement rate falls significantly below actual operating costs, employees in high-mileage roles find workarounds.

When her company moved mileage logging into Navan Expense, submission time dropped from 45 minutes a month to under 10. The finance team's review time dropped further because submissions arrived matched to calendar records, with commuting trips flagged and business purpose pre-confirmed.

When Should You Consider Alternatives to Per-Mile Reimbursement?

The IRS standard mileage method works well for most T&E programs, but two alternatives merit evaluation in specific situations.

A Fixed and Variable Rate (FAVR) program combines a fixed monthly payment with a lower per-mile variable rate. FAVR tends to lower total reimbursement costs for companies with high-volume drivers in specific geographies, because it accounts for local insurance rates and fuel prices rather than a national average. Companies whose field employees average more than 1,000 miles per month often find FAVR reduces total program cost without reducing perceived fairness.

For lower-volume business driving, a flat monthly car allowance or per diem approach may be simpler to administer. Car allowances are generally taxable as income, so the net cost to the employee differs from a per-mile program. A guide to managing business travel expenses covers how companies evaluate these tradeoffs across different employee populations.

A tax professional should review the right reimbursement structure for your specific employee mix, driving patterns, and geography.

Related Terms

• Duty of care: An employer's legal obligation to protect employees during business activities, which extends to personal vehicle use and requires documentation of where employees are driving and for what business purpose.
• Corporate card: A company-issued payment card for T&E expenses, used for hotel, flight, and meal purchases but generally not for mileage, since personal vehicle costs are tracked through mileage reimbursement rather than card transactions.

Sources

[1] Internal Revenue Service, "Standard Mileage Rates," 2026, https://www.irs.gov/tax-professionals/standard-mileage-rates

[2] Motus, "2024 Driving Employee Report," 2024, https://www.motus.com/news/motus-announces-driving-employee-report-2024/

[3] Forrester Consulting, "The Total Economic Impact of Navan Travel and Expense Management," November 2025, https://navan.com/resources/reports/forrester-tei-report-navan

Mileage reimbursement programs run most efficiently when logging, rate application, and submission happen in a single connected workflow. See how Navan Expense automates mileage reimbursement for distributed teams.