Reseller mileage recordkeeping: a log the IRS guidance supports

Miles you drove but can't prove

Resellers drive a lot: thrift store loops, estate sales, the post office, a supplies run, a local pickup across town. Ask most of them in March how many of last year's miles were for the business and you'll get an estimate rounded to the nearest thousand. An estimate written months later is exactly the kind of record IRS guidance gives less weight to. A mileage log kept as you go takes seconds a trip.

This guide covers reseller mileage recordkeeping, based on IRS Publication 463's recordkeeping chapter and IRS guidance on business records, checked November 8, 2026. It deliberately doesn't cover deduction methods or rates, which change and depend on your situation; ask a tax professional how to use your log.

What IRS Publication 463 says a car record should show

Publication 463's table of how to prove certain business expenses lists these elements for car expenses:

The same chapter says you should record the elements of an expense or business use at or near the time, supported by documentary evidence, and that a timely kept record has more value than a statement prepared later when accurate recall is lacking.

Step 1: Record the odometer at the start of the year

Write down the odometer reading on January 1, or the day you start using the car for the business, and again on December 31. That gives you total miles for the year, which Publication 463 lists as one of the elements. Take a dated photo of the dashboard each time.

Step 2: Log each business trip as it happens

For every trip, record:

• Date.
• Starting point and destination, such as "home to Main St thrift, two estate sales, post office, home".
• Business purpose, such as "sourcing" or "drop off 6 parcels".
• Miles, from the odometer or a trip meter.

A notes app, a small notebook in the glove box, or a spreadsheet tab all work. What matters is that the entry is made the same day.

Step 3: Split mixed trips honestly

Many reseller trips mix business and personal stops: groceries after the post office, or a thrift stop on the way to a family visit. Note the stops and record only the miles that were for the business. If you can't separate them sensibly, write down what you did and ask your tax professional how to treat it.

Step 4: Keep the supporting evidence

Publication 463 describes documentary evidence as something that shows amount, date, place and essential character. For a reseller, receipts that tie trips to places, such as a thrift store receipt with a date and address, a post office receipt or a scan record, back up the log. Keep them with the log for the same period. The missing receipts guide covers what to do when a purchase receipt is lost.

Worked example: one Saturday in the log

In this chosen example, a seller logs a Saturday of sourcing and shipping. The mileage figures are illustrative.

The grocery leg is recorded with zero business miles so the day's route is complete and honest.

Step 5: Use a regular route note where it fits

Publication 463 gives an example of a sales representative on an established route who can record the route length once, then the date of each trip and the total miles for the year. If you run the same weekly loop of stores, record the loop's distance once with the stores listed, then log each date you drive it. Any change to the loop gets a new entry.

Step 6: Consider sampling only with care

Publication 463 says you can keep an adequate record for parts of a tax year and use it to prove business use for the whole year, as long as you can show by other evidence that those periods are representative. Resellers' driving often swings with seasons and sales, so a sample may not be representative. Logging every trip is usually simpler.

How long to keep the log

Publication 463 says you generally must keep records that support a deduction for 3 years from the date you file the return on which it's claimed, and longer in some situations. The tax records manual covers retention in more detail. Keep your log with the year's other records.

Apps: Mileage apps can record trips automatically. Check each trip they log and add the business purpose, because an app can record distance but not why you drove.

Common mistakes

• Reconstructing the year's miles from memory.
• Forgetting the January and December odometer readings.
• Logging whole days as business when stops were personal.
• Leaving out the business purpose.
• Losing the receipts that tie trips to places.

Write it before you park

A mileage log entry made the same day, with date, route, purpose and miles, is worth more than any estimate made in spring. Photograph the odometer twice a year, log each trip as it happens, and keep the receipts with the log.