Filed an Extension? Finish Your 2025 Mileage Before October 15

General tax education, not tax advice. Rules below are from IRS Publication 463 (2025), Notice 2025-5, the 2025 Schedule C and IRS pages on extensions and penalties, checked October 1, 2026. Have a tax professional look at anything unusual.

Here is who this is for. You drive for Uber, DoorDash, Instacart or Amazon Flex, or you are a 1099 contractor who drives to clients. In April you filed an extension because the year was a mess. Now it is October, your preparer has emailed asking for "total business miles for 2025", and you have two weeks, a 1099 and no log.

This page is the two-week version. The deeper method for rebuilding a log is in how to reconstruct a mileage log after the fact. Here we stick to what the October deadline changes: the date, the 2025 rate, the questions Schedule C asks, and what to do if you run out of time.

The numbers you need for a 2025 return

Sources: IRS "Get an extension to file your tax return"; Notice 2025-5; Publication 463 (2025); IRS "Failure to file penalty". All checked October 1, 2026.

What does the October 15 extension actually cover?

Only the paperwork. The IRS puts it plainly: an extension gives you until October 15 to file without penalties, and "the extension is only for filing your return." Tax you owed for 2025 was due in April 2026. If you didn't pay it then, interest and the late-payment penalty have been running on the unpaid part since, and filing sooner doesn't undo that, though it stops a second penalty starting.

Two exceptions are worth a minute. If you live in an area the IRS gave disaster relief, your date may be later; check the IRS's tax relief in disaster situations page for your county. And if you were living outside the US in April you may have had a different automatic extension. For everyone else, October 15 is the date.

Which mileage rate do you use for 2025?

One rate for the whole year: 70 cents a mile for business miles driven in 2025. Publication 463 states it as "70 cents ($0.70) per mile from January 1–December 31 for 2025." There was no mid-year change in 2025.

That matters because most of what you will read right now is about 2026's two rates, 72.5¢ through June 30 and 76¢ from July 1. Those apply to miles you are driving this year. Putting 2026 rates on a 2025 return overstates the deduction.

A worked example: a delivery driver who can support 9,400 business miles for 2025 multiplies 9,400 by $0.70 and gets $6,580 of car expense for Schedule C line 9. Business parking and tolls go on top, because the rate doesn't cover them (see parking and tolls with the standard mileage rate). Gas, insurance and repairs don't, because the rate already does.

If 2025 was your first year, this return decides your method

This is the part extension filers miss. Publication 463: "If you want to use the standard mileage rate for a car you own, you must choose to use it in the first year the car is available for use in your business. Then, in later years, you can choose to use either the standard mileage rate or actual expenses." For a leased car, "you must use it for the entire lease period."

So if you started gig work in 2025 and claim actual expenses on this return, you can't switch that car to the standard rate later. If you aren't sure which comes out higher, standard mileage vs actual expenses walks through the comparison. Settle it before October 15, not after.

What does Schedule C ask about your car?

If you take car expenses on Schedule C line 9 and don't have to file Form 4562, you answer Part IV of the 2025 Schedule C. It asks:

• Line 43: when you placed the vehicle in service for business (month, day, year).
• Line 44: of the total miles you drove in 2025, how many were (a) business, (b) commuting and (c) other.
• Lines 45 and 46: whether the car was available for personal use off duty, and whether you have another vehicle for personal use.
• Line 47a: "Do you have evidence to support your deduction?"
• Line 47b: "If 'Yes,' is the evidence written?"

Line 44 means you need the car's total 2025 miles, not only the business ones, and the three numbers have to add up. Line 47 means you will be answering, on the form, whether you have written evidence. That is why the next two weeks should go into records, not into estimating. If you aren't sure what belongs in line 44b, read business miles vs commuting miles first.

How do you build a 2025 mileage log in two weeks?

Publication 463 sets the standard for missing records: you must prove each element with "your own written or oral statement containing specific information about the element" and "other supporting evidence that is sufficient to establish the element." It also says that for a driver, "the nature of your work, such as making deliveries, provides circumstantial evidence of the use of your car for business purposes. Invoices of deliveries establish when you used the car for business." That is what you are building: specific rows, each backed by something dated.

1. Days 1–2: get the total. Find two odometer readings that bracket 2025: oil-change or tire invoices, state inspection reports, a dealer service record, an old photo of the dash. Work out what the car drove in the year. Your business miles must fit inside it.
2. Days 3–5: pull every dated record of work. Download each platform's 2025 tax summary and trip or delivery history, and keep the files. Add the bank deposits that line up with them, client invoices, calendar entries and fuel receipts. If Google Maps Timeline was on, it still shows where the phone went each day; it doesn't show why.
3. Days 6–9: write one row per work day or work block. Date, where you went (first pickup area to last drop-off is enough for a delivery block), the business purpose ("DoorDash evening shift", "parts run for client job") and the miles. Use the platform's miles where it gives them. Add miles the platform doesn't count, like driving to the next offer, only for days where you have the shift on record, and only at a figure you could explain.
4. Days 10–11: take out what doesn't belong. Your drive from home to your regular work place is commuting. Personal stops come out. If two apps were on at once, don't add both apps' miles. What counts as a business mile covers the edge cases.
5. Day 12: reconcile and hand over. Total the business rows, check they sit comfortably inside the car's total miles, and send your preparer the log, the total-miles calculation and a list of which records each month came from. Keep all of it; Publication 463 says to keep records that support a deduction for 3 years from the date you file.

What if you can't support all the miles by October 15?

File anyway, with the miles you can support. The failure-to-file penalty is 5% of the unpaid tax for each month or part of a month the return is late, up to 25%. A return more than 60 days late has a minimum penalty too. Waiting to perfect a mileage figure can easily cost more than the miles are worth.

If records turn up after you file, such as a missing platform history or a service invoice that settles the total, the fix is an amended return on Form 1040-X within its time limit. How to amend a return for missed mileage covers the window and what to attach. What you shouldn't do is round up now and hope.

Where TaxMiles fits, and what it can't do

We make TaxMiles, so weigh this section with that in mind. It tracks drives automatically from the day you install it, so it can't recover 2025 drives it never saw. What it can do for this job:

• Enter 2025 trips by hand. Tap Add, then Manual Trip ("Log past drive"), and set the date and time to the day you drove. The app prices each trip at the rate for its date, so a 2025 trip comes out at 70¢, not 2026's rate. A round-trip switch logs the return drive as a separate trip, and saved route templates speed up a route you drove often.
• Export by tax year. The CPA Export screen has a tax-year picker, so 2025 trips export apart from 2026 ones: a cover letter, a Schedule C CSV and a detailed trip log. Per-trip exports are part of Pro; the free plan includes one summary PDF per tax year.

What it won't do: it doesn't connect to Uber, DoorDash or any gig platform to pull your history, it doesn't decide whether a drive was commuting, and it doesn't file your return or an extension. Trips you type in today are still a reconstruction, whatever app they are typed into.

Make 2026 the year you don't do this again

Publication 463 says you don't have to write down every trip on the day: "If you maintain a log on a weekly basis that accounts for use during the week, the log is considered a timely kept record." A short weekly mileage log review is enough. For 2026, remember the split: miles before July 1 at 72.5¢, from July 1 at 76¢. The fields a log needs are in IRS mileage log requirements.

Frequently asked questions

When is the extended deadline for 2025 tax returns?

If you filed an extension (Form 4868) by the April deadline, your 2025 federal return is due Thursday, October 15, 2026. The extension covered filing only. Any tax you owed was still due in April, and interest and late-payment penalties run on what is unpaid. Areas under IRS disaster relief can have a later date.

What mileage rate do I use on my 2025 return?

70 cents a mile for business miles driven in 2025, the whole year (IRS Notice 2025-5). 2025 had no mid-year change. The 72.5 cent and 76 cent rates are for 2026 miles, not 2025 ones.

Can I still claim mileage if I didn't keep a log in 2025?

Possibly, but on weaker footing. Publication 463 says that without complete records you must prove each element with your own specific statement plus other supporting evidence, and that delivery invoices can show when the car was used for business. Rebuild dated rows from platform histories, deposits and receipts, and leave out miles you cannot tie to a date.

Should I file late to finish my mileage log?

Generally no. The failure-to-file penalty is 5% of unpaid tax for each month or part of a month the return is late, up to 25%. File by October 15 with the miles you can support. If you later find solid records for more, an amended return (Form 1040-X) is the route, inside its time limit.

Can I use the standard mileage rate if 2025 was my first year driving for gig work?

Yes, and this return is where it is decided. For a car you own, Publication 463 says you must choose the standard mileage rate in the first year the car is available for business use if you want to use it at all. For a leased car you must use it for the entire lease period.