A compliant mileage log records four things for every trip: the date, the destination, the business purpose, and the miles driven. The IRS also expects odometer readings at the start and end of the tax year. The rule that trips people up is timing — records must be made at or near the time of the trip, so a log reconstructed in April is weaker than one that was running all year. Round numbers are the classic red flag, because real driving is rarely a tidy 20 miles.
Tax season is here. The April 15 deadline is approaching, and if you drove for business in 2025, you could be sitting on thousands of dollars in unclaimed deductions. But here's the catch: the IRS won't just take your word for it.
Inadequate mileage records are one of the most common reasons deductions get denied during an audit. The good news? The rules are straightforward once you know them.
Quick answer: An IRS-compliant mileage log records five things for every business trip: the date, the starting point and destination, the business purpose, the miles driven, and your total annual mileage. The log must be contemporaneous — created at or near the time of each trip, not reconstructed from memory at tax time. Paper, spreadsheet, or a GPS app all qualify, as long as every trip has these details. (Source: IRS Publication 463.)
What Are the 5 IRS Mileage Log Requirements?
According to IRS Publication 463, every business trip you deduct must include these five documented elements. Missing even one can put your entire mileage deduction at risk.
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| Element | What to Record | Example |
|---|---|---|
| 1. Date | The date of each business trip | February 15, 2025 |
| 2. Destination | Where you drove (address or name) | ABC Corp, 123 Main St |
| 3. Business Purpose | Why the trip was business-related | Client meeting, delivery, showing |
| 4. Miles Driven | Total miles for the trip | 23.4 miles |
| 5. Total Mileage | Odometer at start and end of year | Start: 45,200 / End: 62,800 |
Why does the IRS need your total mileage?
Your annual odometer readings prove what percentage of your driving was for business. If you drove 17,600 total miles and 12,000 were for business, that's a 68% business-use rate. The IRS uses this to verify that your claimed business miles are reasonable.
What Is the "Contemporaneous" Rule for Mileage Logs?
This is where most people get tripped up. The IRS doesn't just want records — they want records created "at or near the time" the trip occurred. This is called the contemporaneous recordkeeping requirement.
In practical terms, that means logging your trip the same day it happens, or at least within a few days. Our dedicated IRS mileage log page has a quick-reference summary of all five required elements. A mileage log created from memory in March while sitting at your accountant's desk is exactly the kind of documentation the IRS will challenge.
Real consequence: Khan v. Commissioner (2025)
In this recent Tax Court case, a small business owner's mileage deductions were completely denied because their records were reconstructed after the fact rather than maintained contemporaneously. The court found the documentation insufficient under IRC Section 274(d), and the taxpayer lost the entire deduction — not just a portion of it.
This is exactly why automatic mileage tracking apps exist. When your phone records every trip with GPS as it happens, the log is contemporaneous by definition. No memory required, no reconstruction needed. It's the core reason an app beats a spreadsheet for anyone who drives for business regularly.
What Counts as an IRS-Acceptable Mileage Log?
The IRS does not require a specific format. All of the following are acceptable, as long as they're accurate, complete, and created at or near the time of travel:
- A mileage tracking app that automatically records trips with GPS — the gold standard for contemporaneous records
- A spreadsheet or digital log updated consistently after each trip
- A paper logbook kept in your vehicle and filled in after each drive
- A written diary or notebook with all five required elements per trip
The key word is consistent. Whatever method you choose, use it for every trip, every time. Gaps in your log are gaps in your defense. If you'd rather an app produce the audit-ready record for you, our TrakMiles Pro vs. TripLog comparison looks at how each builds and exports its logs and what you get at each price.
Sample mileage log (what a compliant entry looks like)
Here's a sample of an IRS-compliant mileage log. Each business trip gets its own row with all the required details. You can copy this format into a spreadsheet or notebook — or let an app build it automatically:
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| Date | Start → Destination | Business Purpose | Miles |
|---|---|---|---|
| 03/04/2026 | Home → 1420 Oak St, then FedEx on Main | Client signing + document drop-off | 18.3 |
| 03/04/2026 | FedEx → 88 Harbor Dr | Second signing appointment | 9.1 |
| 03/05/2026 | Home → Costco Business Center | Supply run (printer paper, toner) | 12.6 |
| 03/06/2026 | Home → Downtown parking garage | Courthouse filing for client | 7.4 |
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Notice the details: real addresses (not "around town"), specific purposes (not just "work"), and exact mileage to the tenth (not round numbers). A running annual total goes at the bottom. That's what makes a log defensible.
7 Red Flags That Trigger IRS Scrutiny
IRS auditors are trained to spot patterns that suggest a mileage log was fabricated or inflated. Avoid these common mistakes:
- Round numbers everywhere — If every trip is exactly 10, 25, or 50 miles, it looks estimated rather than measured
- 100% business use claimed — If you only own one vehicle, claiming every single mile as business is an immediate red flag
- No days off — Claiming business miles 365 days a year strains credibility
- Inconsistent distances — The same client visit showing 15 miles one week and 40 miles the next raises questions
- Suspiciously uniform handwriting — Paper logs that appear to be filled in all at once (same pen, same style) suggest after-the-fact creation
- No supporting documentation — No calendar entries, client emails, or receipts that corroborate your trips
- Excessive annual mileage — Claiming 50,000+ business miles without a job that requires heavy driving (like delivery or field sales) invites questions
How automatic tracking eliminates these risks
GPS-based mileage trackers like TrakMiles record exact distances (not round numbers), capture real start/end locations, timestamp every trip automatically, and distinguish between driving days and days off. The result is an audit-ready log that no one could fabricate — because it's generated by your phone's GPS in real time.
How Long Must You Keep Your Records?
The IRS requires you to keep mileage records for at least 3 years from the date you file the return claiming the deduction. If you claimed a loss, keep them for 7 years.
This means your 2025 records (filed in 2026) should be retained until at least 2029. Cloud-backed mileage tracking apps handle this automatically — your records are stored in your Google Drive and accessible whenever you need them.
Standard Mileage Rate or Actual Expenses: Which Log Do You Need?
You have two methods for calculating your vehicle deduction. Most gig workers and small business owners prefer the standard mileage rate because it's simpler and often more favorable:
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| Factor | Standard Mileage Rate | Actual Expenses |
|---|---|---|
| Calculation | Miles × IRS rate (70¢ for 2025) | Gas + insurance + repairs + depreciation × business % |
| Recordkeeping | Mileage log only | Mileage log + all expense receipts |
| Best for | Fuel-efficient or high-mileage vehicles | Newer, expensive vehicles |
| Switching | Must choose in first year of business use | Can't switch to standard later for owned vehicles |
Important: You need a mileage log either way
Even if you use the actual expenses method, you still need an accurate mileage log to calculate your business-use percentage. There's no way around tracking your miles.
Your mileage deduction lands on Line 9 of Schedule C — and for most drivers it's the single largest line on the whole form. To see exactly where it fits alongside your other deductions, see our complete Schedule C guide for self-employed and gig workers, which walks the form line by line.
Quick Math: What's Your 2026 Deduction Worth?
At 72.5 cents per mile (Jan–Jun) or 76 cents per mile (Jul–Dec), the numbers add up fast. Use our free mileage tax calculator to see exactly what your miles are worth:
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| Business Miles | Tax Deduction | Tax Savings (24% bracket) |
|---|---|---|
| 5,000 miles | $3,500 | $840 |
| 10,000 miles | $7,000 | $1,680 |
| 15,000 miles | $10,500 | $2,520 |
| 25,000 miles | $17,500 | $4,200 |
That's real money — potentially thousands of dollars back in your pocket. But only if you have the records to back it up.
Already Behind on 2025? Here's What You Can Do
If you didn't track your 2025 miles consistently, all is not lost. While reconstructed logs carry more risk than contemporaneous records, the IRS does accept them if backed by corroborating evidence:
- Google Maps Timeline — If you had location history enabled, it may show your driving patterns
- Calendar entries — Client meetings, job sites, and appointments establish where you drove
- Bank and credit card statements — Gas purchases in specific locations corroborate trips
- Invoices and work orders — Proof you had business at specific destinations on specific dates
- Odometer records — Oil change and service receipts often include mileage readings
Reconstruct what you can, document your methodology, and resolve to track automatically going forward.
The simplest way to stay compliant is a GPS tracker built for how you drive. If you deliver or ride-share, see the platform-specific setup for a DoorDash mileage tracker, an Uber mileage tracker, an Uber Eats mileage tracker, an Instacart mileage tracker, a Lyft mileage tracker, a Grubhub mileage tracker, or a Walmart Spark mileage tracker — each explains exactly which miles that app leaves out of your deduction.
Never Miss a Deductible Mile Again
TrakMiles automatically detects when you're driving and records every trip with GPS — creating the contemporaneous, IRS-compliant log you need. Plus, track your earnings, hours, and see your dollars-per-mile in real time.
Start Your 14-Day Free TrialGetting the rest of your records ready too? Our Self-Employed Tax Preparation Checklist for 2026 brings your income, expenses, receipts, mileage, estimated payments, and Schedule C preparation into one checklist.
Tax Season Checklist
Before you file your 2025 return, make sure you have:
- Complete mileage log with date, destination, purpose, and miles for every business trip
- Odometer readings from January 1, 2025 and December 31, 2025 (or check your service records)
- Business-use percentage calculated — business miles ÷ total miles for the year
- Records backed up — stored digitally where they won't get lost for 3+ years
- Trips classified — each trip marked as Business, Personal, or Other
- 2026 tracking set up — start the new tax year right with automatic tracking from day one
Frequently asked questions
What does the IRS require in a mileage log?
Per IRS Publication 463, every business trip you deduct must record five things: the date of the trip, your starting point and destination, the business purpose, the miles driven, and your total annual mileage. A log missing any of these elements can have the deduction disallowed in an audit.
What does an IRS-compliant mileage log look like?
An acceptable log lists each business trip on its own row with the date, destination, business purpose, and miles driven, plus a running total. It can be a paper logbook, a spreadsheet, or the automatic record produced by a GPS mileage tracking app. The format does not matter to the IRS; what matters is that every trip has the required details and was recorded at or near the time it happened.
Does the IRS require a contemporaneous mileage log?
The IRS strongly prefers a contemporaneous log, meaning one created at or near the time of each trip. A log reconstructed from memory months later, such as at tax time, carries far less weight and is a common reason mileage deductions are reduced or denied in an audit. Recording trips as they happen, or using an app that does it automatically, is the safest approach.
How long do I need to keep my mileage records?
Keep your mileage logs and supporting records for at least three years from the date you filed the return, which is the general IRS statute of limitations for an audit. If you underreported income substantially the window extends to six years, so many drivers keep records for six or seven years to be safe.
Do I need a separate mileage log for each delivery app?
No. The IRS cares about total business miles, not which app generated them. You can keep one combined log for all your gig platforms, as long as each trip records the date, destination, business purpose, and miles. Time spent driving for business across DoorDash, Uber, Instacart, and others all counts as deductible business mileage on the same log.