Can I Reconstruct a Mileage Log After the Fact?
No credit card required
Technically you can attempt to reconstruct a mileage log, but the IRS and Tax Court treat reconstructed logs with deep skepticism — and they're frequently disallowed in full under IRC §274(d). Cases like Sanford v. Commissioner make clear that a reconstructed log backed by corroborating evidence can sometimes survive, but a pure memory-based reconstruction almost never does. Here's what you need to know if you're in this situation and how to protect yourself going forward.
What the Law Says About Reconstruction
IRC §274(d) requires "adequate records or sufficient evidence corroborating the taxpayer's own statement" for vehicle expense deductions. The IRS's own regulations under Temp Reg §1.274-5T specify that records should be made "at or near the time of the expenditure." A log assembled from memory months or years later is the opposite of contemporaneous.
The consequence is severe: unlike most deductions where the Cohan rule allows reasonable estimates, mileage is listed property. No contemporaneous records means no deduction — period. Tax Court has upheld this position in dozens of cases.
The Cohan rule lets taxpayers estimate some deductions when records are incomplete. Congress explicitly excluded listed property (which includes vehicles) from this rule when it enacted §274(d). You cannot estimate your way to a mileage deduction. You need records or you lose the deduction.
What Sanford v. Commissioner Teaches Us
In Sanford v. Commissioner, the Tax Court examined a taxpayer who claimed substantial vehicle expense deductions but produced only a reconstructed log compiled after the IRS began examining the return. The court disallowed the deductions, noting that the reconstruction was based on general recollection rather than corroborated by contemporaneous evidence.
The key takeaway from Sanford and similar cases is that reconstruction isn't automatically fatal — but it must be corroborated by independent contemporaneous evidence. A reconstructed log that matches up with booking confirmations, contractor invoices, credit card receipts, and calendar entries has a fighting chance. A log pulled from memory with no supporting documents does not.
Corroborating Records That Can Strengthen a Reconstructed Log
If you're reconstructing a log for a past year, gather every piece of contemporaneous evidence you can find to corroborate each trip. The strongest corroborating records for STR hosts:
Airbnb and Platform Records
- Booking confirmations with guest check-in and checkout dates
- Guest communications in Airbnb messenger (showing you coordinated a visit)
- Platform transaction history showing when revenue was earned
Financial Records
- Credit card or bank statements showing purchases at supply stores near your STR
- Gas station receipts or card charges near your property's location
- Contractor or repair invoices with property address and service date
Calendar and Communications
- Google Calendar or iCal entries with property visit notes
- Text messages or emails coordinating trips (with contractor, cleaner, or guests)
- Home security system logs showing access events on specific dates
- Smart lock entry logs from systems like Schlage or August
No credit card required
How to Build the Strongest Possible Reconstruction
If you need to reconstruct a past year's mileage log, work with a CPA and follow this approach:
- Start with Airbnb bookings. Pull every checkout date. For each checkout, you likely made a property visit. That gives you a minimum trip count anchored to real, documented dates.
- Pull credit card statements. Identify every charge at supply stores, hardware stores, and gas stations. These corroborate dates and locations.
- Review contractor invoices. Every repair visit has a date. If you were present, that's a documented trip.
- Check your phone's location history. Google Maps Timeline or iPhone Significant Locations can show you were at your property on specific dates — this can be exported and used as corroborating evidence.
- Be conservative. Only log trips you can corroborate with at least one independent piece of evidence. Uncorroborated trips are the ones that get disallowed.
If you're reconstructing mileage for a year under audit, do not do it alone. A qualified CPA who handles IRS audits can help you build the strongest defensible record and communicate with the IRS examiner in a way that preserves as much of your deduction as possible. See our STR CPA prep checklist for what to gather before that meeting.
Start Tracking Properly Going Forward
Reconstruction is stressful, expensive, and yields a fraction of the deductions you'd have gotten with real-time tracking. The fix for future years is simple: use a mileage tracking app that captures trips automatically the moment you start driving. You add the business purpose — one line, ten seconds — and the log is done.
For the full breakdown of what a proper log must contain, see our mileage log requirements guide. For everything you should be deducting as an STR host, the complete Airbnb tax deductions guide covers it all.
Never Need to Reconstruct Again
DeductFlow tracks your STR business miles in real time with GPS precision — so your log is always contemporaneous, always complete, and always audit-ready.
Start Free →Pro from $19/month or $149/year · 7-day free trial · No credit card required
Related Reading
No credit card required
Disclaimer
This article is for informational purposes and does not constitute tax, legal, or financial advice. Tax rules vary based on your specific situation, filing status, entity structure, and jurisdiction. Always consult a qualified CPA or tax professional for guidance on your specific tax situation. IRS rules and thresholds are subject to change — verify current requirements at irs.gov before filing.