Excite Tax's answer for Utah owners: IRC §274(d) requires proof, and IRS Publication 463 wants each trip's date, miles, destination and business purpose, logged at or near the time.
For every business trip: the date, the miles, the destination and the business purpose. For the year: the date the car started being used for business and the total miles driven. Excite Tax's short version is that the log has to let a stranger rebuild the business-use percentage, because the regulation measures business use in miles against the car's total use for the year. The full list is below.
Yes, and it needs only six columns: date, odometer start, odometer end, miles, destination and business purpose. Excite Tax's sample, with filled-in rows, is below; copy the columns into any spreadsheet. The IRS prints its own version as Table 5-2, a daily business mileage and expense log.
For 2026 it changed mid-year: 72.5 cents a mile for business driving from January 1, then 76 cents a mile for driving on or after July 1, 2026. For a 2025 return still being finished, the rate is 70 cents a mile. The rates by date are below.
No. The regulation says a contemporaneous log is not required, and a log kept weekly that accounts for the week's use counts as a timely kept record. A log written in March for the year before is the weak kind; see timing.
Yes. A record of a car's business use kept in a computer with a logging program is an adequate record. An app records where the car went, not why, so the business-purpose column still has to be filled in by a person.
No. Driving between home and a main or regular place of work is personal commuting, however far it is. The exception that matters for many owners is a home office that is the principal place of business; see commuting.
Rebuild it from evidence, not memory. Amounts that are approximated or estimated cannot be deducted, so a round number like 10,000 miles is the one thing not to write. How to reconstruct is below.
A car is listed property, which includes any passenger automobile. For listed property, IRC §274(d) allows no deduction unless the taxpayer substantiates the amount, the time and the business purpose by adequate records or by sufficient evidence corroborating the taxpayer's own statement. That is stricter than the rule for an ordinary expense, where a receipt and a bank line usually carry the proof (how receipts work). For a car, the log is the proof.
The amount of each business/investment use ... based on the appropriate measure (i.e., mileage for automobiles ...), and the total use of the listed property for the taxable period. (ii) Time. Date of the expenditure or use
Read plainly, the regulation asks for three things about a car: how much of its use was business, measured in miles against the total for the year; the date of each use; and the business purpose. Excite Tax builds every mileage log on those three, plus the destination, because IRS Publication 463 lists the business destination among the records to keep for car expenses.
What a mileage log records, and where the requirement comes from
| Record | What to write | Source |
|---|---|---|
| Date of each trip | The day you drove | Publication 463: the date of the use of the car |
| Miles for each business trip | Odometer start and end, or the trip distance | Publication 463: the mileage for each business use |
| Destination | The town or client site | Publication 463: your business destination |
| Business purpose | Who you saw or what you did, in a few words | A written statement of business purpose is generally required |
| Total miles for the year | Odometer on January 1 and on December 31 | Publication 463: the total miles for the year |
| Date the car started business use | Once, when the car enters service | Publication 463: the date you started using it for business |
| Parking and tolls | The receipt or the transponder statement | Deductible on top of the standard mileage rate when business-related |
A round trip with several stops can be one line: several uses that form a single use, such as a round trip, can be recorded once, and a lunch stop between two business stops is not an interruption. A route that never changes can be recorded once too; for a delivery route, the regulation accepts the year's total miles, the route's length recorded once, and the date of each trip.
The purpose column is where most logs fail. "Client" is a start; "Measure kitchen for remodel bid" is a record. Where the business purpose is evident from the surrounding facts, a written explanation is not required, which is why a salesperson on a fixed route gets more latitude than an owner with one car for everything.
The word owners hear is "contemporaneous," and the regulation is more forgiving than that: a contemporaneous log is not required, but a record made at or near the time has a credibility that a statement prepared later lacks. IRS Publication 463 accepts a log kept weekly as timely. Excite Tax's recommendation is the weekly one: ten minutes on Friday with the calendar open.
A full year of entries is not the only option. An adequate record kept for part of the year can prove business use for the whole year, if other evidence shows those periods are representative. The IRS's own example is an owner who logs the first week of every month, finds business use of 75%, and supports the rest of each month with invoices and bills. Sampling works for steady driving patterns and fails for seasonal ones; a landscaper who drives twice as much in June cannot sample January.
The template is six columns: date, odometer start, odometer end, miles, destination and business purpose. That covers each element in Publication 463's list for car expenses and matches the layout of the IRS's own Table 5-2, without the expense columns. The sample below is a Sandy-based designer's week that straddles the July 1, 2026 rate change; the last column is not part of the log, it shows which rate each trip earns.
Sample mileage log (the six template columns, plus the rate each trip earns)
| Date | Odometer start | Odometer end | Miles | Destination | Business purpose | Rate that applies |
|---|---|---|---|---|---|---|
| 2026-06-29 | 40,980 | 41,026 | 46 | Lehi, tile supplier showroom | Pick up tile samples for bathroom remodel job | 72.5 cents |
| 2026-07-06 | 41,212 | 41,250 | 38 | Provo, client home | Measure kitchen for remodel bid | 76 cents |
| 2026-07-08 | 41,301 | 41,327 | 26 | Salt Lake City, client office | Present design options, round trip | 76 cents |
| 2026-07-10 | 41,390 | 41,421 | 31 | Draper, then Murray | Two client site check-ins, one round trip with a lunch stop | 76 cents |
The four trips total 141 miles, and the June trip is 46 miles at 72.5 cents, or $33.35, and the three July trips are 95 miles at 76 cents, or $72.20, for $105.55. The Draper-and-Murray line is one record because a lunch stop between two business stops does not interrupt business use.
Business standard mileage rate by period
| Driving done | Business rate per mile | Source |
|---|---|---|
| During 2025 | 70 cents | IRS Publication 463 (2025) |
| January 1 to June 30, 2026 | 72.5 cents | IRS News Release IR-2025-128 |
| July 1 to December 31, 2026 | 76 cents | IRS Announcement 2026-11 |
The mid-year change is the reason the date column matters more than usual this year: the 76-cent rate applies to driving on or after July 1, 2026, and the earlier rate keeps applying to miles before that date, so a log with only a yearly total cannot say which rate each mile earns.
Three rules sit around the rate. Business parking fees and tolls are deductible in addition to the rate, but parking at your regular workplace is commuting. To use the standard rate for a car you own, you must choose it in the first year the car is available for use in the business; for a leased car, you must use it for the whole lease. And a business that uses five or more cars at the same time cannot use the standard rate for any of them. The rates apply to fully electric and hybrid cars as well as gasoline and diesel ones.
A designer based in Sandy drives one car 18,000 miles in 2026 and logs 9,000 business miles, 4,000 before July 1 and 5,000 after, which is 50% business use, figured the way Publication 463 divides a mixed-use car, by miles driven for each purpose.
The designer's standard mileage deduction for the year
| Period | Business miles | Rate | Deduction |
|---|---|---|---|
| January 1 to June 30 | 4,000 | 72.5 cents | $2,900 |
| July 1 to December 31 | 5,000 | 76 cents | $3,800 |
| Business parking and tolls, from receipts | Added to the rate | $140 | |
| Total | 9,000 | Two rates, split by date | $6,840 |
Without dates on the trips, the split is guesswork, and approximated or estimated amounts cannot be deducted. Without the year's total of 18,000 miles, there is no business-use percentage to show; Schedule C asks for business, commuting and other miles separately, so the odometer reading on January 1 is part of the log.
Driving between home and your main or regular place of work is a personal commuting expense no matter how far it is, and business calls or a colleague in the car do not change that. Leave those miles out of the business column; they still count in the year's total.
The IRS names the trips from home that are not commuting. The one that covers most owners without a shop: when your home is your principal place of business, travel to another work location in the same business is deductible, whether that location is regular or temporary and regardless of distance. Two others: travel to a temporary work location in the same business when you have at least one regular work location away from home, and travel to a temporary work location outside the metropolitan area where you live and normally work. For a contractor driving to job sites, that distinction decides most of the log (construction bookkeeping covers job costing).
A sole proprietor claiming car expenses answers vehicle questions on the return. Schedule C Part IV asks for business, commuting and other miles, whether you have evidence to support the deduction, and, if so, whether the evidence is written. A log is how those answers become "yes" and "yes"; the Schedule C instructions point to Publication 463 for the records car expenses require.
An owner who works for their own corporation is an employee of it, and the usual route is a reimbursement rather than a deduction on a personal return. The log is still the proof. Under an accountable plan, the employee adequately accounts by giving the employer a record in which each expense was entered at or near the time, along with documentary evidence of travel and mileage. The standard rates also set the reimbursed amount that is deemed substantiated, so an employer paying 76 cents a mile for July driving is paying the published rate, not a guess. Excite Tax keeps these reimbursements in the corporation's books as a separate expense line, so the log and the ledger reconcile.
Without adequate records, each element has to be proved by your own specific statement, written or oral, plus other corroborating evidence. In practice that means rebuilding trip by trip from the calendar, invoices, client addresses and phone location history, then measuring each distance on a map. It is slower and weaker than a log, and it still cannot rest on an estimate.
Excite Tax's order for a missing year: rebuild the business trips from dated evidence, take the year's total miles from service records or inspection reports that show the odometer, and start a real log today so next year does not repeat it. If the rest of the books are behind too, fixing messy books is the wider version of the same job.
Keep it with the return it supports, generally for 3 years after filing, with longer periods for some records. The full schedule is in what records the IRS requires. An app's export belongs in storage the business controls, not only inside the app.
Hand the books over when keeping them costs more hours than the business can spare, or when they stop agreeing with the bank.
Excite Tax keeps these books; the return they feed is reviewed and signed by a licensed CPA at TBD CPA LLC.
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