Tax records

Keeping a Mileage Log for Tax Deductions

A practical guide to logging business mileage for deductions: what records the IRS expects, standard rate vs actual cost, and how to log trips with SnapReceipt.

Business Miles Are Real Money

For trades and makers who drive to job sites, suppliers, and client meetings, business mileage can be a significant tax deduction, but only if it is documented. Undocumented miles are not deductible, and reconstructing a year of driving from memory does not satisfy a tax authority. A simple, consistent mileage log turns ordinary driving into a legitimate deduction.

What A Good Mileage Log Records

Tax authorities generally expect a contemporaneous record: the date, the business purpose, the start and end points, and the miles for each trip. The key word is contemporaneous, meaning logged at or near the time of the trip, not invented later. A log kept as you go is both easier and far more defensible than one assembled at tax time.

Standard Rate Or Actual Cost

Two common methods exist: a standard mileage rate that multiplies business miles by a set per-mile figure, or the actual-cost method that tracks the real expense of operating the vehicle. The standard rate is simpler and needs only a mileage log; actual cost needs receipts for fuel, maintenance, and more. Many drivers choose the standard rate for its simplicity, but the right choice depends on your situation.

Log Trips As You Go

The hard part of mileage logging is consistency, not complexity. Logging each business trip when it happens, with a phone tool like SnapReceipt that records mileage alongside your receipts, keeps the record contemporaneous and complete. Capturing the trip in the moment beats trying to remember weeks of driving, and it keeps mileage and expense records in one place.

Keep It With Your Other Records

Mileage is one piece of a business spending picture that also includes material and tool receipts. Keeping the mileage log together with those receipts, privately on your device, makes tax time a matter of review rather than reconstruction. Consult a tax professional for your specifics, but a clean, contemporaneous log is the foundation either way.

Data charts

Mileage log quality and audit defensibility (relative)
Mileage log quality and audit defensibility (relative) Contemporaneous logs hold up best; memory-based reconstructions are the weakest at audit. Values: Logged per trip 95, Weekly recap 70, Monthly guess 40, From memory 10. 024487195 95Logged per trip70Weekly recap40Monthly guess10From memory
Contemporaneous logs hold up best; memory-based reconstructions are the weakest at audit.
What a trip record needs (count of fields)
What a trip record needs (count of fields) A defensible trip record captures these basics each time: date, purpose, route, and miles. Values: Date 1, Purpose 1, Start/end 2, Miles 1. 01122 1Date1Purpose2Start/end1Miles
A defensible trip record captures these basics each time: date, purpose, route, and miles.

Compare

Mileage methods

MethodRecords neededEffortBest for
Standard rateMileage logLowMost drivers
Actual costLog plus all vehicle receiptsHighHigh vehicle costs
No logNoneNoneNo deduction allowed
ReconstructedEstimatedHigh, weakLast resort only

Field Checklist

  • Log every business trip as it happens.
  • Record date, purpose, route, and miles.
  • Choose standard rate or actual cost deliberately.
  • Keep mileage with your receipt records.
  • Consult a tax professional for your situation.

FAQ

Common questions

What does a mileage log need to include?

Generally the date, business purpose, start and end points, and miles for each trip, recorded at the time.

Standard rate or actual cost, which is better?

The standard rate is simpler and needs only a mileage log; actual cost can be larger but needs full vehicle receipts.

Can I reconstruct mileage at tax time?

It is far weaker than a contemporaneous log and may not satisfy an audit. Log trips as they happen.

How do I keep a mileage log easily?

Log each trip in the moment with a tool like SnapReceipt that records mileage alongside receipts.

Sources

Data and references