How to Keep a Mileage Log the IRS Will Accept
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A mileage log the IRS will accept records four things for every business trip: the date, the destination, the business purpose, and the miles — written at or near the time you drove, not reconstructed in April. For 2026 there is a wrinkle that catches people out: the standard business rate changed mid-year, so a single multiplication across the whole year gives the wrong number. The rates, the exact log format and a worked year are below. (This is an organisational guide, not tax advice — confirm specifics with your tax professional.)
The 2026 standard mileage rates
| Period | Business | Medical / moving | Charitable |
|---|---|---|---|
| 2026, Jul 1 – Dec 31 | 76¢/mile | 23.5¢ | 14¢ |
| 2026, Jan 1 – Jun 30 | 72.5¢/mile | 20.5¢ | 14¢ |
| 2025 (full year) | 70¢/mile | 21¢ | 14¢ |
Sources: IRS Notice 2026-10 (the 2026 rates) and Announcement 2026-11, IRB 2026-29, which revised the business rate to 76¢ for expenses “paid or incurred … on or after July 1, 2026”. Both read 2026-09-09. The charitable rate is set by statute, not by the IRS, which is why it alone never moves. Rates change — check the IRS before you file.
The mid-year change is the part worth slowing down for. Most guides quote one 2026 business figure, and whichever one they picked is wrong for half the year. It also means your log needs dates, not just a total — a year-end number of "about 6,000 miles" cannot be split across two rates, so it cannot be calculated correctly even if it happens to be accurate.
What every entry needs
The IRS asks for adequate records covering the time, place and business purpose of the travel, kept timely. In practice, four columns:
| Column | Example | Why it matters |
|---|---|---|
| Date | 2026-07-14 | Places the trip in the right rate period |
| Destination | Acme Co., Riverside | The "place" element |
| Business purpose | Site survey for quote | The element people leave blank, and the one that carries the claim |
| Miles | 34 | Odometer start/end, or the trip distance |
"Business purpose" is where weak logs fail. "Client" is not a purpose. "Site survey for quote, Acme Co." is. It takes four extra words at the time and is unreconstructable later.
A worked year, across the rate change
A contractor drives 6,200 business miles in 2026 — about 124 a week — split 2,900 in the first half and 3,300 in the second:
| Period | Miles | Rate | Deduction |
|---|---|---|---|
| Jan–Jun | 2,900 | 72.5¢ | $2,102.50 |
| Jul–Dec | 3,300 | 76¢ | $2,508.00 |
| Correct total | 6,200 | $4,610.50 | |
| If you used 76¢ all year | 6,200 | 76¢ | $4,712.00 — overstated by $101.50 |
| If you used 72.5¢ all year | 6,200 | 72.5¢ | $4,495.00 — understated by $115.50 |
Neither error is enormous, and that is exactly why it goes unnoticed for years. Overstating is the one with consequences. What the $4,610.50 is actually worth depends on your bracket: self-employment tax alone is about $651 of it, and at a 22% marginal income rate the combined saving is roughly $1,666. Run your own numbers through the mileage deduction calculator.
One more figure that argues for logging every trip: a single 18-mile round trip missed once a week for a year is 900 miles — $684 of deduction at the second-half rate, gone because nobody wrote it down.
Standard rate or actual expenses?
Two methods, and you generally choose per vehicle:
| Standard mileage rate | Actual expenses | |
|---|---|---|
| What you track | Business miles only | Every fuel, insurance, repair, depreciation and registration cost, plus miles to work out the business-use percentage |
| Effort | One log | A log and a full cost file with receipts |
| Usually better for | Efficient, paid-off, lower-cost vehicles driven a lot for work | Expensive vehicles, heavy repair years, low business mileage |
Either way you keep the mileage log — the actual-expense method still needs business miles to compute the business-use share. There are also rules about which method you may switch to in later years, particularly if you claimed depreciation, so that is a question for your accountant rather than a blog.
What counts as a business mile
- Counts: office to client, client to client, to a supplier or the bank, to a temporary work site, to a business meeting or trade event.
- Does not count: commuting — home to your regular place of work, in either direction. This is the single most common error in an amateur log, and it is usually the largest number in it.
- Depends: if your home is your principal place of business, trips from home to clients can qualify. Worth confirming for your situation, because it changes the total substantially.
Spreadsheet setup
Five columns: Date, Destination, Purpose, Miles, and Period. Make the last one calculate itself so the rate split never depends on you remembering:
- Period:
=IF(A2<DATE(2026,7,1),"H1","H2") - First-half miles:
=SUMIF($E:$E,"H1",$D:$D) - Deduction:
=SUMIF($E:$E,"H1",$D:$D)*0.725 + SUMIF($E:$E,"H2",$D:$D)*0.76 - Sanity check on blanks:
=COUNTIF(C:C,"")-1should be 0 — every trip has a purpose
Log from your phone the moment you park. The whole system depends on that one habit, and no amount of formula design substitutes for it.
Common mistakes
- Reconstructing at year end. "I probably drove about 8,000 miles" is an estimate, and estimates are what the contemporaneous-records rule exists to exclude.
- Claiming the commute. Large, tempting, and not deductible.
- Logging a total instead of trips. Un-splittable across rate periods and unsupportable if questioned.
- Leaving purpose blank and intending to fill it in later. You will not remember.
- Using one rate for all of 2026. The specific trap this year.
- Keeping the log and losing the odometer readings — note the start-of-year and end-of-year odometer, since total annual miles are what the business-use percentage is measured against.
Related: mileage deduction calculator · tracking business expenses for taxes · self-employed deductions checklist · how much to set aside for taxes
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Quick FAQ
What is the IRS mileage rate for 2026?
The business rate is 72.5 cents per mile for 1 January to 30 June 2026 and 76 cents per mile for 1 July to 31 December 2026. Because it changed mid-year, business miles must be totalled separately for each half and multiplied by the matching rate. The 2025 rate was 70 cents for the whole year. Always confirm against the IRS page before filing.
Does the IRS require a mileage log?
To claim a vehicle deduction you need adequate records substantiating the time, place and business purpose of the travel, kept at or near the time of the trip. There is no mandated format — a spreadsheet, a notebook or an app all qualify — but there is a required content, and a reconstructed estimate does not meet it.
What does a mileage log need to include to be accepted?
Date, destination, business purpose and miles for each trip, recorded contemporaneously. Keep your start-of-year and end-of-year odometer readings too, so total annual mileage is on record alongside the business portion.
What is the best mileage log book for taxes?
The one you will actually fill in. A paper book in the glovebox works if you write in it every time; a spreadsheet on your phone works if you open it every time. The format is not what gets audited — the completeness and timeliness are. What a spreadsheet adds over paper is that the rate split and the totals calculate themselves.
How do I keep track of mileage for taxes without it being a chore?
Log at the moment you park, not at the end of the day, and keep the entry to four fields. If your trips repeat — the same handful of sites — save them as rows you can copy, so a logged trip is two taps rather than typing an address. The failure mode is never a hard log, it is a delayed one.
Can I switch between the standard rate and actual expenses?
There are restrictions, and they depend on which method you used first for that vehicle and whether you claimed depreciation. It is a genuine "ask your accountant" question, and worth asking before the first year rather than after, because the first choice constrains the later ones.
Do I still need a mileage log if I use actual expenses?
Yes. The actual-expense method needs your business-use percentage, and that is business miles divided by total miles — so the log is required either way. The difference is that you also keep every vehicle cost receipt on top of it.