What are the IRS requirements for a mileage log?
The IRS requires contemporaneous records to support vehicle expense deductions — meaning records made at or near the time of the business trip, not reconstructed months later at tax time. **Required elements for each trip:** 1. **Date** of the business trip 2. **Destination** (city or address, not just 'office') 3. **Business purpose** (e.g. 'client meeting with ABC Corp', 'picking up supplies for project X') 4. **Miles driven** for the business trip 5. **Odometer readings** (beginning and end) — technically required but often satisfied by recording total miles **Annual documentation:** - Record your odometer at the start of the year and end of the year - Calculate total personal miles and business miles - Business percentage = business miles ÷ total miles **Acceptable formats:** Paper log, spreadsheet, or a mileage tracking app (MileIQ, Everlance, TripLog, Hurdlr). The IRS accepts digital records. **The Cohan Rule exception:** The Tax Court has allowed some mileage deductions without perfect records if the taxpayer can demonstrate a pattern of business use. However, relying on the Cohan Rule is risky — contemporaneous logs are far safer. **Commuting exclusion:** Miles from home to a regular office are commuting — never deductible. However, if you have a qualifying home office, all trips from your home are business miles.
- Record: date, destination, business purpose, and miles for each trip
- Contemporaneous records required — not reconstructed at year-end
- Odometer readings at start and end of year recommended
- Apps (MileIQ, Everlance) create IRS-compliant logs automatically
- Home-to-regular-office trips are commuting — not deductible