Tax · 5 min read

Business Mileage Log Guide

Mileage is one of the largest small business deductions — and one of the first the IRS disallows when the log is sloppy or recreated after the fact.

What the IRS wants in the log

  • Date of each trip
  • Business purpose
  • Starting and ending odometer or total miles
  • Destination

Standard mileage vs. actual expense

Standard mileage is simpler and usually larger for newer, fuel-efficient vehicles. Actual expense (gas, insurance, depreciation, repairs) often wins for heavy trucks and high-cost vehicles. Pick one method in year one of a vehicle.

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Common mistakes

  • Reconstructing the log from memory at tax time
  • Counting commute miles as business
  • Mixing personal trips into a tracked business drive

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