Mileage logbook rules for tax deductions
The IRS requires a mileage log with five specific elements for each business trip — and the records must be kept at or near the time of the trip, not reconstructed later. Here is exactly what the IRS requires and what a compliant log looks like.
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On this page: The 5 required elements · Contemporaneous records rule · Paper log vs mileage app · Annual records to keep · What an inadequate log looks like · Example entry · How long to keep records · Related lookups · FAQ
MileIQ — GPS-stamped mileage logs that satisfy all 5 IRS requirements automatically
MileIQ logs date, destination, distance, and time for every trip automatically. Swipe to classify business or personal. Export an IRS-ready annual report.
The 5 elements the IRS requires in every mileage log entry
Under IRS Publication 463, the following five elements must be recorded for each business trip to fully substantiate a mileage deduction:
- Date of the trip — the calendar date the driving occurred
- Destination — the name or address of where you went (or a description: "client office, downtown Seattle")
- Business purpose — a brief description of the business reason for the trip (one sentence is sufficient: "project meeting with [client]" or "supply pickup for job site")
- Miles driven — the number of miles for the trip, or odometer start and end readings
- Total odometer reading — annual start-of-year and end-of-year odometer readings to establish total miles driven
Elements 1–4 are per-trip entries. Element 5 is annual. The combination of per-trip entries plus annual odometer readings allows the IRS to verify total miles and calculate the business-use percentage.
The contemporaneous records rule
The IRS requires that mileage records be contemporaneous — made at or near the time of each trip. This is the most important rule and the one most commonly violated.
- Contemporaneous means: Recorded the same day as the trip, or within a few days — while the details are fresh
- Not contemporaneous: Reconstructing months of trips from memory at tax time, or creating a log in December for the entire year
- Why it matters: Courts have consistently upheld IRS disallowance of mileage deductions where logs were clearly reconstructed rather than maintained in real time
A mileage tracking app solves this completely — every trip is GPS-stamped at the time of travel. This is the strongest possible contemporaneous record because the timestamp cannot be altered retroactively.
Paper logbook vs mileage tracking app
| Method | Contemporaneous? | IRS-compliant? | Practical notes |
|---|---|---|---|
| Paper logbook | Yes — if filled in at time of trip | Yes | Requires discipline; easy to forget entries; harder to audit-proof |
| Spreadsheet or notes app | Yes — if updated at time of trip | Yes | More flexible than paper; same discipline requirement |
| GPS mileage tracking app (MileIQ, Everlance) | Yes — automatically | Yes — all 5 elements captured | Strongest option: GPS timestamp, automatic entry, business/personal classification, annual report export |
| Year-end reconstruction from memory | No | No — not acceptable | Deduction may be fully disallowed on audit |
| Calendar/appointment book alone | Partial | Partial — missing miles and odometer | Useful as supporting evidence but insufficient on its own |
Annual records to keep alongside the mileage log
- Odometer reading January 1 (or the date you started using the vehicle for business)
- Odometer reading December 31 (or the date you stopped using it)
- Total miles for the year — calculated from the odometer readings
- Total business miles for the year — summed from individual log entries
- Business-use percentage — business miles ÷ total miles × 100
What an inadequate mileage log looks like
Common log failures that trigger IRS disallowance:
- Entries with no business purpose — "drove for work" without a client, destination, or project
- Round numbers that look estimated — "100 miles Monday, 100 miles Tuesday" every week for a year
- Missing trips that correspond to days invoices were issued or client work was done
- 100% business use with no personal trips whatsoever — implausible for most personal vehicles
- Log created in December or January for the prior year with the same pen and handwriting throughout
- No odometer readings — impossible to verify total annual miles or business-use percentage
Example: Three log entries that meet IRS requirements
| Date | Destination | Business purpose | Miles |
|---|---|---|---|
| 2026-03-04 | 123 Main St, Bellevue | Project kickoff meeting — Acme Corp | 22 |
| 2026-03-07 | Home Depot, 456 Oak Ave | Supply run — job materials for Smith project | 8 |
| 2026-03-11 | Downtown conference center | Industry trade show — client prospecting | 15 |
Each entry has all five required elements. The business purpose is specific enough to connect to actual business activity. These would withstand IRS scrutiny.
How long to keep mileage logs
- Standard retention: 3 years from the date you file the tax return for the year in which the mileage was driven
- If underreported income: 6 years — the IRS can audit back 6 years if income was understated by more than 25%
- If depreciation was claimed: Keep records until 3 years after you dispose of the vehicle and stop depreciating it
TurboTax Self-Employed — Import mileage data and report on Schedule C
TurboTax Self-Employed accepts mileage reports from tracking apps, guides you through Schedule C vehicle questions, and confirms you have checked "written evidence" on the return.
FAQ
What does a mileage log need to include for IRS purposes?
The IRS requires five elements for each entry: (1) date, (2) destination, (3) business purpose, (4) miles driven, and (5) annual odometer start/end readings. All five must be present for the log to fully substantiate the deduction under IRS Publication 463.
Can I recreate a mileage log at tax time?
No. The IRS requires contemporaneous records — made at or near the time of each trip. A log recreated from memory is not contemporaneous and is significantly weaker on audit. Courts have consistently disallowed or reduced mileage deductions when logs were reconstructed rather than kept in real time.
Is a mileage tracking app an acceptable mileage log?
Yes. GPS mileage tracking apps (MileIQ, Everlance, Hurdlr) are fully acceptable IRS mileage logs. The app records date, destination, distance, and time automatically with GPS timestamps — satisfying the contemporaneous requirement and capturing all five required elements. The annual report they generate can be used directly for tax purposes.
How long should I keep my mileage log?
Keep mileage logs for at least 3 years after filing the return for the year the mileage was driven. Keep for 6 years if income was significantly underreported. Keep until 3 years after disposing of the vehicle if you claimed depreciation.
What happens if I don't have a mileage log and I'm audited?
Without a log, the IRS can disallow the entire mileage deduction. Vehicle expenses are specifically designated as requiring strict substantiation — the Cohan rule (estimates) generally does not apply. Supporting evidence like calendar entries and client invoices can help, but cannot substitute for a compliant contemporaneous log.
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Last reviewed: April 14, 2026