Filing on Extension? Your October 15 Mileage Checklist
If you filed Form 4868 for your 2025 return, it is due Thursday, October 15, 2026. Before you file, make sure your 2025 mileage log is complete: every business drive with its date, destination, purpose and miles, valued at the 2025 rate of 70 cents a mile.
An extension buys time to finish the return, and the mileage deduction is usually the part that needed it: the log is the one record nobody else sends you. Your bank, your clients and the delivery platforms mail their forms in January. The miles are yours to produce. Here is what to check in the days before the deadline.
The date, and what the extension did not extend
The automatic six-month extension moved the filing deadline for 2025 individual returns from April 15 to October 15, 2026. It did not move the payment deadline. Tax owed for 2025 was due in April, and interest (plus any late-payment penalty) has been running on unpaid tax since then — so filing promptly, with an accurate deduction, stops that clock from running on a larger number than it needs to.
Not sure whether you are on extension?
If you or your preparer filed Form 4868 by April 15, 2026 (or paid with an extension payment), you are. If you are unsure, ask your preparer or check your IRS online account before assuming the later date applies to you.
Your 2025 mileage checklist
- Every business drive is in the log. The IRS expects a record of each trip's date, destination, business purpose and miles. A year total on its own is not a log.
- Every drive is classified. An unclassified drive is not in your deduction. Clear the backlog before you add anything up.
- Commutes are out. Driving from home to your regular workplace is personal, however far it is — here is where the line falls.
- The rate is right. The 2025 business rate was 70 cents a mile for the whole year. Medical and moving miles were 21 cents, charity miles 14 cents.
- Tolls and parking are added on top. Business tolls and parking are deductible in addition to the standard rate — what counts.
- You know your total miles for the year. Schedule C asks for business, commuting and other miles for each vehicle. Odometer readings from service invoices bracket the year if you did not write one down on January 1.
Missing drives from 2025?
October is late, but it is not too late to fill a gap honestly. A log reconstructed from real evidence — calendars, invoices, delivery history, location history — is defensible. A weekly average stretched across the year is not.
Two sources usually hold most of what is missing:
- Another mileage app. If you tracked part of 2025 in MileIQ, Everlance or Driversnote, export a CSV and import it into Mile. You preview every row first, and duplicates are skipped.
- Google Maps Timeline. If Timeline was on, your phone may remember drives you never logged. Mile's Timeline import lets you pick the ones that were for business and adds them with the distance already worked out.
Hand your preparer a report, not a pile
Once the year is complete, Mile's year report lists every business drive with its date, purpose, miles and the rate used, with totals by purpose and by vehicle. Export it as a PDF or CSV (Premium), or email it straight to your preparer from the app. On a computer, Mile on the web lets you classify a backlog with the keyboard in one sitting.
Then make next year easier
If 2025 took an extension because of the mileage, 2026 does not have to. Turn on automatic tracking now and the rest of this year logs itself — including the mid-year rate change, since 2026 drives are valued at 72.5 cents through June 30 and 76 cents from July 1.
This article is general information, not tax advice. Your tax professional has the final word on your return.
This article is general information about US federal tax rules, not tax advice for your situation. Rates and rules change — check IRS.gov or ask a tax professional before you file.