Country guide · United States

The IRS does not require a contemporaneous log — it requires the total miles for the year

What "adequate records" means

Publication 463 asks for two different things, and only one of them is per trip.

Per trip: the date, the destination, the business mileage, and the business purpose.

Per year: Table 5-1's Transportation row, verbatim — "the cost of the car and any improvements, the date you started using it for business, the mileage for each business use, and the total miles for the year."

That last item is the one people leave out, and it is the one the whole deduction turns on: the business-use percentage is business miles over total miles, and a log of business trips supplies only the numerator.

Contemporaneous is not the standard

26 CFR § 1.274-5T(c)(1): "A contemporaneous log is not required, but a record … made at or near the time of the expenditure or use … has a high degree of credibility."

And (c)(2)(ii)(A) is explicit that "a log maintained on a weekly basis, which accounts for use during the week, shall be considered a record made at or near the time of such use." Publication 463 says it plainly too: "You don't need to write down the elements of every expense on the day of the expense."

So the standard is at or near the time, and a weekly log meets it. Advice insisting on a same-day entry is stating as a requirement the one thing the regulation goes out of its way to disclaim.

The IRS also accepts a computer record without qualification: "if you prepare a record on a computer, it is considered an adequate record."

The odometer is not asked for, and is still the best way to the year's total

The word odometer appears exactly once in the whole of Publication 463 — on Table 5-2, under a heading reading "THIS IS NOT AN OFFICIAL INTERNAL REVENUE FORM".

That is worth saying because "the IRS requires odometer readings" is a claim in wide circulation, and it is not in the publication. Reading the odometer on the first and last day of the year remains a sound way to arrive at the year's total, and a better one than summing recorded trips — it is a measurement rather than an accumulation of them. It is a method, not a rule.

2026 is a two-rate year

Notice 2026-10 § 3 set 72.5 cents. Announcement 2026-11, on 13 July 2026, revised it to 76 cents "on or after July 1, 2026", with the earlier rate continuing "before July 1, 2026".

One year, two figures, split at 1 July — so a single rate applied across the year is wrong in one direction for half of it.

The employee deduction is gone; the reimbursement is not

Notice 2026-10 § 3: the OBBBA made permanent the disallowance of all miscellaneous itemized deductions, "Thus, the business standard mileage rate provided in this notice cannot be used to claim an itemized deduction for unreimbursed employee travel expenses." The suspension is IRC § 67(h), with carve-outs for reservists, fee-basis state and local officials, certain performing artists, eligible educators, and impairment-related work expenses.

What survives, and what most people actually need, is the accountable plan. Rev. Proc. 2019-46 § 7.01(1) deems substantiated "the lesser of the amount paid under the mileage allowance or the business standard mileage rate multiplied by the number of substantiated business miles." The rate still applies; the document is a reimbursement claim rather than a deduction.

A driver of an employer-provided vehicle has no per-mile figure of their own at all — Pub. 463: "If you use a vehicle provided by your employer for business purposes, you can deduct your actual unreimbursed car expenses. You can't use the standard mileage rate."

Eight states make reimbursement compulsory — not three

The rate is federal and the record requirements are federal, but whether an employer must pay at all is state law. Five states command an indemnity for what the job costs: California (Lab. Code § 2802(a)), Illinois (820 ILCS 115/9.5(a)), Montana (MCA 39-2-701), North Dakota (NDCC 34-02-01) and South Dakota (SDCL 60-2-1). Massachusetts reaches the same ground through its travel-time rule, 454 CMR 27.04(4)(b) and (d) — (b) for being sent somewhere other than the regular work site, (d) for travel between places during the work day. New Hampshire (RSA 275:57, I) and Iowa (§ 91A.3(6)) are weaker: they put a 30-day clock on an expense the employer asked for or authorised, which is a deadline for paying rather than a duty to authorise.

None of the eight prescribes a rate, and most employers use the IRS figure.

Where none of them applies there is still a federal floor rather than nothing: 29 CFR 531.35 requires wages to reach the employee "free and clear" and treats an expense the employer requires as a violation "in any workweek when the cost … cuts into the minimum or overtime wages". A car is that shape of expense, measured by the same log.

What changes in those states is your position, not your arithmetic: an unreimbursed business mile is a claim against the employer rather than merely a deduction you can no longer take — and the mileage log is the evidence for it.

How long to keep it — there is no number

26 CFR § 1.6001-1(e) requires records to be kept "so long as the contents thereof may become material in the administration of any internal revenue law". IRC § 6001 sets no period at all.

In practice the floor is the assessment limitation of IRC § 6501 — three years from filing, six where more than 25 % of gross income was omitted, and unlimited for a fraudulent or unfiled return. But a mileage log outlives all three: Pub. 463 requires the business-use record "for each year of the recovery period", and a car is 5-year MACRS property depreciated over six calendar years. A depreciating filer's log sits on a six-plus-three chain.

An employee who hands records to an employer and is reimbursed "generally don't have to keep copies", and 26 CFR § 1.274-5T(e) moves the duty to the employer — with exceptions, including a nonaccountable plan and claiming more than the reimbursement.

What failure costs

Not a penalty. Under IRC § 274(d), without substantiation the deduction simply does not exist.

Why an app rather than a notebook

Nothing above requires software, and the regulation explicitly blesses a weekly log written from memory. What software changes is the denominator. Business trips get written down because somebody is going to claim them; total miles do not, and total miles is half of the fraction the whole deduction is computed from.

DriveHub records every drive in the background — business and personal — and asks afterwards which were which, so the year's total is measured rather than estimated. The report prints the date, the destination, the business purpose in your own words and the mileage per trip, and the year's opening and closing odometer readings as their own block, which is how it arrives at the total. A trip that fell before or after 1 July 2026 is priced at that half of the year's rate.

This page states what Publication 463 and the regulations say, and cites them so you can check. It is not tax advice. It can't account for your circumstances. Where money is involved, ask your tax preparer — and bring the log.