Mileage Logbook Requirements

In a recent U.S. Tax Court case, Sharon A. Struble v. Commissioner T.C. Summary Opinion 2022-1, the court made clear what the expectations are for a mileage logbook. A mileage log is a spreadsheet or logbook that holds records of the number of miles that a taxpayer has traveled in their vehicle for business purposes over a period of time. Taxpayers can use a mileage log to claim a tax deduction or reimbursement from their employer.

Sharon Struble was employed by the U.S. Air Force to perform certain duties that involved her caring for individuals with health care issues, providing them with financial guidance incidental to their health problems and participating in death notifications. Her work involved travel between various military bases in Texas. Furthermore, her travel expenses for these duties were not eligible for reimbursement.

To document her travel, Ms. Struble kept a ledger that documented her miles driven. She updated this ledger quarterly using a calendar that was claimed to be kept contemporaneously. The entries in the ledger did not indicate the nature of the business being conducted nor did it indicate that these were non-reimbursable costs.

The court noted the strict requirements under the Internal Revenue Code (“IRC”) when maintaining such a log. Taxpayers must maintain a log in such a manner as to substantiate:

• The amount of the mileage expense
• The time/place of the travel
• The business purpose of the travel

There is no requirement to keep a contemporaneous log. However, when reconstruction later is substantial, corroborative evidence supporting such reconstruction is necessary.

The court found Ms. Struble’s mileage log to be insufficient and did not meet the requirements of the IRC. Therefore, the court disallowed her mileage deduction.