The mileage deduction is usually the biggest write-off a gig or 1099 driver has. It is also the one that disappears if the only number you can show is a year-end guess. Keep a log that can answer five questions about each work trip — when, where, why, how far, and how that sits against total miles on the car — and you keep the deduction you actually drove. Lose those fields, and the rate on the poster does not matter.
This page is the statute-shaped checklist: what Publication 463 and the vehicle substantiation rules expect. The weekly habit that produces those rows is in how to keep an IRS-ready mileage log. How long the file has to outlive tax season is in how long to keep mileage logs.
The short version: one row per business trip with date, destination or route, business purpose, and miles, plus year-start and year-end odometer readings. Write it down at or near the time you drove. In 2026 the date also stamps the rate: 72.5¢ through June 30 and 76¢ from July 1. A platform “year in review” is not that log. A reconstruction is weaker than a live one. Education, not tax advice.
The five required elements of an IRS mileage log
IRS Publication 463 and the regulations under IRC Section 274(d) expect these pieces for each business trip, plus a way to show total miles on the vehicle:
- Date of the trip. The specific day you drove, not a week range. In 2026 this field also decides 72.5¢ or 76¢.
- Destination or route. Where you went. “Downtown” is thin. “LAX TBIT / Lyft drop” or “Chipotle on Sunset → 14th St drop” is usable.
- Business purpose. Why the trip was work. “Business” by itself is not enough. “Uber airport ride” or “DoorDash from Chipotle” is.
- Miles driven. The actual distance. Odometer start/end or GPS-tracked miles both work. “About 20” does not.
- Total miles on the vehicle. Year-start and year-end odometer readings so business, commuting, and personal can be checked against the car. See how to keep an odometer photo log.
A screenshot that says “you drove 12,400 miles” is a total, not a log. The five fields, and the file a CPA can actually open, are spelled out for tax-season handoff in how to export your mileage log for your CPA.
2026’s two rates: the date field now does double duty
This year is the trap that was not in the February version of this page. The IRS raised the business standard mileage rate mid-year:
| When you drove | Business rate | What the log must show |
|---|---|---|
| January 1 – June 30, 2026 | 72.5¢ per mile | First-half business miles, dated |
| July 1 – December 31, 2026 | 76¢ per mile | Second-half business miles, dated |
One annual total × one rate is the wrong deduction. The app or spreadsheet has to stamp the rate in effect on that trip’s date. Worked example, not a promise: 8,000 business miles in the first half and 9,000 in the second half is $5,800 + $6,840 = $12,640. The same 17,000 miles at 72.5¢ all year would understate the deduction by $315. The split how-to is in how to apply the 2026 rate change and the July 1 explainer.
The contemporaneous requirement
Accuracy is not enough. Publication 463 wants records made at or near the time of the trip. That is the contemporaneous recording rule. A December spreadsheet filled from memory is the pattern examiners have seen before.
What will not hold: a log created at year-end from memory, a single week of identical round-number trips, or a platform year-in-review with no dates, destinations, or purpose. Cars are listed property. The Cohan estimate rule that sometimes rescues other expenses does not fill in missing vehicle miles. If you already stopped tracking, use the reconstruction guide and label rebuilt months honestly.
You do not have to write the row at a red light. Same day is the habit that survives a real gig week. Within a few days is still contemporaneous in spirit. A March reconstruction of January is not. What to write in that purpose line, and how to salvage a forgotten trip the same evening, is same-day mileage notes vs April reconstruction.
What looks thin if someone asks
Most gig returns are never examined. That is not a reason to skip the log. These patterns make a claimed mileage deduction harder to defend if questions arrive:
- Business miles that cannot fit the car. Work + commute + personal have to sit inside the odometer delta. If reconstructed work miles overflow the car, revise down.
- Round numbers on every row. Real GPS miles are 7.4 and 18.1, not 10 and 20 forever.
- 100% business use on a personal car. Grocery runs and school pickup still happen. A honest personal slice is more credible than 98%.
- A large Line 9 with no log. Schedule C can show the dollars. The examiner will still ask for the rows. See how to claim car expenses on Schedule C.
- One blended 2026 rate. June trips and July trips are not the same cents.
Gig-driver specifics the five fields have to carry
Uber, Lyft, DoorDash, and Instacart year-end estimates usually cover paid trips on that app. They miss unpaid stretches between offers, the other apps you ran the same day, and anything you classified wrong. One physical mile is one deduction — do not add three platform totals together. The multi-app rule is in how to track mileage across Uber, Lyft, and DoorDash.
Purpose has to match the commute rule, not just “the app was open.” Home to a regular hotspot is usually commuting. The first paid pickup, a reposition while you are available for work, and unpaid deadhead miles between paid trips are usually business. Fuzzy first-trip-of-the-day cases live in what counts as a business mile and business vs. commuting miles.
What typically happens if vehicle expenses are examined
If a return is selected for vehicle expenses, the request is usually paperwork, not a raid:
- A letter. Documentation for the vehicle deduction: the mileage log, registration, and anything that supports the rows.
- A review of the five fields. Are they there? Do they look written near the trip dates? Do June and July 2026 use different rates?
- Cross-checks that already exist. Calendar, platform history, fuel or toll dates, odometer bookends, and map distances between claimed points.
- A determination. Adequate records, the deduction stands. Missing fields, those trips (or the whole claim) can be reduced or disallowed.
The Cohan rule is not a safety net for cars
Cohan v. Commissioner lets a court estimate some expenses when you can prove something was spent but the receipts are incomplete. Passenger automobiles are listed property. Publication 463 and Treas. Reg. 1.274-5T want strict substantiation for vehicle use. Do not plan on a judge estimating your Uber miles. Reconstruct what you can from independent records, then start a live log.
How to make the log harder to knock over
Use GPS-verified tracking if you will actually classify the same day
A GPS app records timestamps, coordinates, and distance you did not type from memory. That is useful only if you swipe business vs. personal while you still remember the trip. A pile of unclassified drives in December is how people either miss miles or guess purpose. Four methods, and why auto-detect grades highest for a gig week, are in how to track mileage for taxes.
Write a purpose a stranger could understand
“Client meeting” is thinner than “Met Johnson & Associates to review the website proposal.” For gig work, the platform plus the job type is enough: “Lyft, airport drop” beats “work.”
Record personal miles too
Year-start and year-end odometer photos, plus a reasonable personal slice, show you are not pretending the car never went to the grocery store. A 70% business-use year is more believable than 98% on a daily driver.
Keep the files that prove the boxes
Calendar entries, invoices with addresses, platform trip exports, and fuel or toll dates corroborate the log. You do not need a receipt for every mile. You do need the log itself, and you should export it before you delete the app.
Back the file up outside the phone
A paper notebook that lives only in the door pocket is one car wash away from gone. Cloud backup or a CSV in a folder you control is the record that survives a cracked screen.
Digital vs. paper: the IRS accepts both
The IRS does not require an app. Paper works if the five fields are there and the notes are contemporaneous. Digital has practical advantages:
- Timestamps that show the row was not typed in April.
- GPS distance you did not estimate.
- Forced fields so a tired 10 p.m. swipe still has a date and miles.
- Exportability — CSV for the rows, PDF for the packet.
Best practice: one log, GPS-verified if you will classify the same day, odometer photos at the bookends, 2026 first-half and second-half subtotals, and a copy saved outside the app. That is the combination that answers every question on this page.
How long to keep the mileage records
Do not use a vibes-based “seven years for everything.” The everyday habit follows the assessment / refund window: generally 3 years from filing the original return (or the due date if you filed early), or 2 years from payment if that is later. A 2026 log supports the 2026 return you file in 2027 — so the three-year mark is not January 1, 2030. Keep records longer if a large slice of income never made the return, and indefinitely if you filed no return. Vehicle basis records travel with the car because standard mileage includes depreciation.
The full keep-until table, and why you export before you delete an app, is in how long gig drivers should keep mileage logs.
What to do if you have not been tracking
- Start a live log today. Future miles will be contemporaneous. Do not wait for January 1.
- Reconstruct what you can, and label it. Platform history, calendars, Maps Timeline, and odometer proof. Weaker than a live log. Better than a round guess. Steps: reconstruct a mileage log after the fact.
- Photograph today’s odometer. That is the bookend going forward.
- Do not invent trips. A smaller documented deduction beats a larger fabricated one.
Keep the five fields without writing them at every red light
TaxMiles: Mileage Tracker (App Store id 6758579463) auto-detects trips, lets you classify them the same day, stamps 72.5¢ or 76¢ by trip date, and exports an IRS-ready PDF or CSV. Free is 40 trips a month. Not MileIQ. Not Everlance. Not Mileage Tracker for Taxes (id 6758426140).
Get TaxMiles on the App StoreFrequently Asked Questions
What five things must an IRS mileage log include?
Date, destination or route, business purpose, miles, and a way to show total miles on the vehicle. Publication 463 is the source. A dollar total without those fields is not a log.
Does a 2026 mileage log need two IRS rates?
Yes. 72.5¢ through June 30 and 76¢ from July 1, by the date you drove. Do not multiply one yearly total by either rate. Mechanics: the mid-year 76¢ change.
Can the IRS access my phone’s GPS data?
The IRS does not get your phone’s location history just because you claimed mileage. You can voluntarily provide a GPS-tracked export as supporting documentation. That is your choice, and it only helps if the export has the five fields.
What if I forgot the January 1 odometer reading?
Use the next best dated reading: a service invoice, inspection report, or the earliest photo you have. Photograph today’s odometer and keep going. Bookend method: odometer photo log.
Is a mileage app sufficient as my only record?
Yes, if the records are contemporaneous, the five fields are on the export, and you can show total miles on the car. Paying for the app does not make a sloppy log compliant. Export CSV and PDF to a folder you control.
Can I estimate my business-use percentage from a sample?
You calculate the percentage from actual records, not a vibe. Publication 463 discusses keeping detailed records for a representative period when driving patterns are consistent — that is a sampling method, not a guess. If 2026 has two rates, a sample still needs dates so first-half and second-half miles are not blended. Confirm the current Publication 463 language for your year.
What if my mileage log has some gaps?
A log with minor gaps is still far better than no log. Specific undocumented trips can be disallowed without throwing out the rest. Fill gaps with supporting evidence where you can, and do not dress a reconstruction up as a live row.
How long should I keep the log?
Usually 3 years from filing / 2 years from payment, whichever is later. Longer in a few cases. Full table: IRS record retention for mileage logs.
Related reading: IRS-ready mileage log (the weekly habit), how long to keep mileage logs, odometer photo log, reconstruct after the fact, export for your CPA, apply the 2026 rate split, what counts as a business mile, and MileIQ vs. a free iPhone tracker.
This article is general tax education for U.S. federal Schedule C filers, not legal, tax, or accounting advice and not a guarantee of any deduction or of any audit outcome. Publication 463, Treas. Reg. 1.274-5T, IRC 274(d), Schedule C / Form 4562 instructions, IRS Topic 305, Publication 583, and IRS mileage rates can change; read the current IRS sources (including Notice 2026-10 and Announcement 2026-11) or work with a licensed professional. TaxMiles: Mileage Tracker (App Store id 6758579463) is not affiliated with the IRS, and is not MileIQ, Everlance, or Mileage Tracker for Taxes (id 6758426140).