Rebuild a Lost or Missing Mileage Log: What the IRS Accepts

Can I deduct business miles if I never kept a mileage log, or lost it?

You may, but only with proof of each trip: its date, miles and business purpose, plus the car's total miles for the year. Federal law allows no deduction for a car unless you substantiate it by adequate records or by sufficient evidence corroborating your own statement (26 U.S.C. 274(d)). The IRS puts cars on a short list of items that need this extra proof (Revenue Procedure 2019-46, section 2.03). It applies to any taxpayer claiming the deduction, including a corporation that owns the car.

A missing log removes the easiest proof. The claim can still be supported by other evidence, if that evidence exists. Guesses do not fill the gap: the regulation says the deduction cannot rest on approximations or the taxpayer's unsupported testimony, and it replaced the older court practice of estimating an expense that clearly happened (26 CFR 1.274-5T(a); Publication 463).

A log you write now is not a record made at the time. It counts as your own statement, and it needs corroboration for each element: dated documents or detailed statements from other people who know the facts. Unsupported recollection is not enough.

A case is not simple when:

• more than one year has no log, because each return year needs its own proof;
• an IRS notice or your preparer is asking for the log;
• the miles claimed are well above what any document supports, or do not fit the odometer readings;
• a corporation, a partnership or a second driver is involved;
• the app or phone that held the data is gone.

If any of these fits, the last section, "Different for you?", says where to go next.

Gather first: calendars, invoices or job tickets with addresses, platform trip summaries, service and inspection records with odometer readings, fuel, toll and parking receipts, client emails or texts, the return as filed, and any IRS notice.

What proof of business miles does the IRS accept?

The IRS accepts either adequate records or your own detailed statement backed by other evidence. For a car, the regulation names the elements to prove: the miles of each business use, its date, its business purpose, and the car's total use for the year. Publication 463 adds the business destination (26 CFR 1.274-5T(b)). What a log must show, line by line, is in the mileage log requirements guide. If you kept a real log that is incomplete, the regulation lets the IRS accept other evidence for an element where you have substantially complied with the adequate-records rules; whether yours qualifies is the IRS's call (26 CFR 1.274-5T(c)(2)(v)).

Under the second route, evidence of the date, place or amount of use must be direct evidence, such as a detailed written statement or oral testimony from another witness, or documentary evidence such as receipts and paid bills. Evidence of business purpose can be circumstantial (26 CFR 1.274-5T(c)(3)). Publication 463 gives delivery work as an example: the nature of the work is circumstantial evidence that the car was used for business, and delivery invoices establish when.

Why does a mileage log made at the time carry more weight than one rebuilt later?

The regulation says a record made at or near the time of a trip, supported by sufficient documentary evidence, has a high degree of credibility that a later statement lacks, because people do not accurately recall details afterward. A contemporaneous log is not required, and a log kept weekly for that week's use counts as made at or near the time (26 CFR 1.274-5T(c); Publication 463).

To count as much, a statement made later needs strong backing. Written evidence counts for more than spoken evidence, and more the closer in time it is to the trip. So in a rebuilt log, documents made at the time of the trip, and written evidence generally, are likely to count for more than notes written afterward.

What can I use to rebuild a mileage log after the fact?

Use dated records that show where the car was and when, and dated odometer readings for the year's total miles. The IRS sources name receipts, paid bills, delivery invoices and written statements from people who know the facts. Apart from the destroyed-records rule below and a narrow rule for exceptional circumstances, where the situation itself made fuller evidence impossible to get (26 CFR 1.274-5T(c)(4)), they describe no approved way to rebuild a log. They do not mention calendars, platform history or location data. They do not say whether these count, or how much weight each would get.

To build the list:

1. Fix the odometer. Find dated readings near the start and end of the year. The difference is the car's total miles. If a reading is missing at either end, use the nearest dated readings and mark the year's total as an estimate; a total you cannot support is a reason to get help before you file or answer a notice.
2. List every trip the evidence proves. One row per trip, not per document: date, starting point, destination, purpose. Match all documents for the same trip to one row. A round trip or an unbroken run of business stops can be one row; count each driven leg once (26 CFR 1.274-5T(c)(6)(i)(C); Publication 463).
3. Measure each trip the same way. Check that the evidence shows the car made the trip on that date and to that place. The miles are your own measurement, so write down how you measured them.
4. Name the source on every row, a document or a witness who can confirm it, and keep those documents or statements with the list. A row with no source is an estimate.
5. Total documented rows and estimates separately, and never claim estimated miles as supported ones.
6. Compare the documented total with what the return claimed. If you have not filed yet, the documented total is the figure the evidence supports. If the return is already filed, the gap is the part at risk.

What does a rebuilt mileage log template look like?

A rebuilt log looks like an ordinary log with two added columns: the source of each row, and whether the row is documented or estimated. Publication 463 prints a sample daily log with date, destination, business purpose, odometer start and stop, and miles for the trip (Table 5-2).

A filled row, for illustration: 3/14, shop to 212 Oak St, furnace repair, 18 miles (mapped, round trip), invoice 1041, documented.

Label the whole list as what it is: "Rebuilt on" the real date, the period it covers, and the sources used. The IRS sources give no labeling rule. They weigh a later statement differently from a record made at the time, so a list that says when and how it was made is less likely to be mistaken for one that was not.

What should I never do with a rebuilt mileage log?

Never do these:

• Backdate the list or enter trips as if you logged them on the day. A later list passed off as a record made at the time is false. If the IRS establishes that part of an underpayment is due to fraud, the penalty is 75% of the portion attributable to fraud, and the whole underpayment is treated as fraud except any part you prove is not (26 U.S.C. 6663).
• Fill gaps with round numbers, such as the same distance every Tuesday. Publication 463 says you cannot deduct amounts you approximate or estimate.
• Add trips to reach the miles on the return. The return's number does not make a trip real.
• Count commuting without checking. Trips between home and a regular workplace are generally personal. Exceptions exist, and the mileage log requirements guide covers them.

Schedule C, Part IV (or Form 4562, Part V, if you must file that form) asks whether you have evidence to support the deduction and whether that evidence is written (Schedule C; Form 4562; 26 CFR 1.274-5T(d)). Answer from what you actually have. From today, log at or near the time of each trip and export a copy at year end: an electronic system must be able to retrieve and reproduce your records in legible form (Publication 583).

My app deleted my data or my phone broke: does the destroyed-records rule apply?

Only if the loss was beyond your control, such as a fire, flood or other casualty. The regulation and Publication 463 do not say whether a deleted app account or a broken phone counts. When adequate records are lost through circumstances beyond the taxpayer's control, such as destruction by fire, flood, earthquake or other casualty, the taxpayer has a right to substantiate a deduction by reasonable reconstruction (26 CFR 1.274-5T(c)(5)). Publication 463 describes the same relief and lists fire, flood and other casualties (Publication 463).

Three limits matter:

• They name casualties. They do not say whether a deleted account, a failed phone or a lapsed subscription counts. You must establish that the loss was beyond your control.
• The rule covers records that existed. It does not help with a log that was never kept.
• It allows reasonable reconstruction. They do not define "reasonable". Build it from the dated records above, not from memory.

First find out whether the data can be recovered: ask the app or platform for an export, check email and cloud backups, and look for a copy with a former preparer. Keep proof of what happened: the date, the cause, messages with the app's support, and any repair or replacement record.

Can I log part of the year and use it for the whole year?

Yes, if the logged periods are adequate records and other evidence shows they are representative of the year, unless the car is an employer vehicle that more than one employee can use. This is called sampling (26 CFR 1.274-5T(c)(3)(ii); Publication 463).

Publication 463's example is a record kept in the first week of each month, with invoices and bills showing that business use continued at the same rate in the later weeks. The regulation gives the opposite case: a salesperson whose fourth week each month was delivery week, unlike the other three. That week did not represent the month, so it could not support a year's figure.

Five limits apply:

• An employer's vehicle that is made available to more than one employee for any part of the year cannot be substantiated by sampling (26 CFR 1.274-5T(c)(3)(ii)(B)).
• Each logged period must itself be a record made at or near the time. A week written up later from memory is not a sample.
• Other evidence must show the logged periods are typical. Invoices, bills and a steady work pattern do that; a busy season does not.
• The regulation and Publication 463 speak of periods within a tax year. Neither says a log from one year can stand in for a year with no log.
• A sample gives a share of business use. You still need the year's total miles from odometer readings.

Do I need a mileage log if I use the standard mileage rate?

You still need proof of your business miles, though not necessarily a log kept at the time: a record made at the time is one route, and your own detailed statement backed by corroborating evidence is the other. The standard mileage rate replaces the record of what the car costs to run, not the proof of how far you drove for business. The deduction is the rate times the business miles, and the miles must still be substantiated under section 274(d) (Revenue Procedure 2019-46, sections 2.03 and 4.01; Tax Topic 510).

The business rate changed during the year this page covers. Miles driven January through June are worth 72.5 cents per mile each, and miles driven July through December 76 cents per mile each. Rates for earlier years are on the same IRS page, so use the rate for each trip's own year. Every mile you cannot support removes one mile's worth of rate from the deduction. What the rate covers is in standard rate or actual expenses; what the log must show is in the mileage log requirements guide.

My mileage deductions were denied: what does that cost, and what can I do?

Denied miles raise the tax. The IRS may also add interest and an accuracy-related penalty of 20% of the underpayment caused by negligence, disregard of the rules or a substantial understatement (IRS: Accuracy-related penalty). Several years claimed without a log means several separate exposures, and each year has its own clock: the IRS generally has 3 years from the date you filed (or the original due date, if you filed early) to assess more tax, and fraud or other facts can remove or extend that limit (26 U.S.C. 6501; IRS: Time IRS can assess tax). How far back an examination can go, and what it can cost, are in the IRS audit guide.

If your return is examined, the IRS may ask for more information to establish that your records, statements and documents are accurate and reliable (Publication 463). A rebuilt list goes in as your statement, with the documents behind it. If you can already see that claimed miles cannot be supported, see amending a return for business expense mistakes. If you hold a notice, follow its response instructions and deadline (IRS: Accuracy-related penalty). If the bill is more than you can pay at once, interest and a monthly late-payment penalty keep running on the unpaid balance, and the IRS offers a short-term plan (180 days or less) and a long-term monthly plan (IRS: Payment plans).

Example

These examples use US dollars and round, illustrative numbers.

A rideshare driver whose app lost two years of data

A driver's two returns each claimed 14,000 business miles. The app's data is gone. The platform's trip summaries, downloaded from the driver's account, show the date and the pickup and drop-off points of each trip, and service invoices give the odometer reading at the start and end of each year. The driver measures each listed trip the same way and adds the rows up. Which platform miles count at all is covered in the rideshare driver guide.

The rebuilt list shows 19,000 documented miles and marks the other 9,000 as an estimate, not a record. At an illustrative 65 cents a mile (the real rate differs by year), 9,000 unsupported miles is about $5,850 of deduction at risk. Whether to defend those miles, amend or drop them depends on what other evidence exists and which years are still open.

An electrician with one van and no log

An electrician has no log. Dated job records and 190 invoices support 190 separate trips, each from the shop to a job and back, with no duplicate or combined routes. Measured the same way, the 190 trips total 6,840 miles. Service records put the van's total at 12,000 miles for the year. The list supports 6,840 business miles, a 57% business share. The other 5,160 miles are personal or have no document behind them. The list is titled "Rebuilt from invoices on" the real date, and each row names its invoice number. Supply-house runs with no invoice stay off the list unless a receipt shows the date and place. A trip that starts from home raises the commuting question in the mileage log requirements guide.

A contractor starting a log now

A contractor with no log for the first half of the year starts logging in July, covering the first week of every month. The logged weeks show 900 business miles out of 1,200 total, a 75% business share. Invoices show the same work pattern in the other weeks. That follows the sampling pattern in Publication 463, for the months actually logged. The odometer shows 6,000 miles from July through December. If the logged weeks are representative, the share would support up to 4,500 business miles for those six months (75% of 6,000). For January through June, the log shows nothing by itself. The sampling rule reaches those months only if other evidence, such as dated invoices, shows the logged weeks are representative of them, and the regulation's examples run from an earlier sample to later weeks, not the reverse.

Different for you?

• An IRS notice or your preparer asks for a log you do not have, your app data is gone, or several years of miles were claimed without one: which years are exposed, what evidence can honestly be assembled, and whether to amend, answer the notice or change how miles are recorded turn on facts a list cannot settle. Get bookkeeping help to assemble the evidence and set up records for the years ahead.
• The IRS has opened an audit, or you want to correct a filed return: see the IRS audit guide, which Schedule C expenses get questioned and amending a return for business expense mistakes.
• Whole years were never filed: see catching up on unfiled returns and Schedule C expenses for unfiled years.
• You drive for a rideshare or delivery platform: see rideshare and delivery driver deductions.
• Other receipts are missing too, or the books are behind, not just the miles: see lost receipts for business expenses and catching up on overdue books, and get bookkeeping help.
• An LLC or S corporation owns the vehicle, or a corporation repays your mileage: the corporation's deduction needs the same proof. A repayment under an accountable plan needs an accounting within a reasonable time, so a list built long after the trips may not qualify, and a repayment that fails the plan rules is reported as pay (Publication 463, chapter 6). See buying a vehicle through your business and reimbursing owner expenses.
• You drive a specially built work vehicle: the log rule does not apply to a qualified nonpersonal use vehicle, one that by its nature is not likely to be used more than a de minimis amount for personal purposes (26 U.S.C. 274(d) and (i)). The log rule applies generally to any pickup truck or van unless it has been specially modified (26 CFR 1.274-5(k)(8)). An ordinary pickup, van or car does not qualify.
• You file in Canada: the rules differ; see the CRA logbook guide for a review.