This is general guidance, not personalised tax advice. IRS mileage rates and rules change — check irs.gov or your accountant for current figures.
Vehicle costs are one of the largest expenses a contractor carries, and one of the least accurately tracked. Most reconstruct a rough mileage figure at tax time from memory, or don't claim vehicle costs properly at all because building a log after the fact feels pointless. Neither serves you well — the IRS expects contemporaneous records, and under-claiming a legitimate deduction is money left on the table.
Two ways to claim vehicle costs
- Standard mileage rate — a fixed rate per business mile, updated annually by the IRS, covering fuel, wear and depreciation in one number. Simpler, but you still need a mileage log to support the miles claimed.
- Actual expenses — a business-use percentage of real running costs (fuel, insurance, repairs, depreciation or lease payments), which can be higher for a vehicle used almost entirely for the business, but needs every receipt kept and a clear business-use split.
Whichever method, the mileage log itself is not optional — the IRS expects a record of each business trip, not an estimate produced later.
What a proper mileage log needs
- Date of the trip
- Starting point and destination
- Business purpose — which job it relates to
- Miles driven
Tying each trip to a specific job is where most mileage apps fall short. A generic tracker gives you a yearly total for the IRS. It doesn't tell you that one job needed five extra site visits that quietly ate into its margin.
Why job-level mileage matters, not just the yearly total
A job that needed multiple site visits and extra supply runs costs more in vehicle time and fuel than one finished in a single trip — but if mileage isn't tagged to the job, that cost is invisible until the year's fuel bill is totalled up. Tracking mileage per job shows which jobs are quietly more expensive to run, not just what the total deduction comes to.
Spreadsheet vs app
| Method | What actually happens |
|---|---|
| Memory, reconstructed later | Rough estimate, rarely accurate, doesn't survive an IRS inquiry. |
| Paper mileage log | Accurate if kept up, usually abandoned within a month. |
| Spreadsheet | Works if you log every trip same-day — most people don't. |
| App logging trips per job (like Site Wallet) | A trip logged in seconds, tagged to the job it was for, rolled into that job's real cost. |
How Site Wallet handles vehicle costs
Mileage and fuel receipts tag to a job exactly like any other cost, so a job's running total includes what it actually cost to get there and back — not just materials and labor. At tax time, export the same records for whichever method you or your accountant use to calculate the vehicle deduction.
FAQ
Can I switch between the standard mileage rate and actual expenses?
Generally, if you use the standard mileage rate in the first year a vehicle is available for business use, you can later switch to actual expenses — but switching from actual expenses back to the standard rate has more restrictions. Check with your accountant before switching methods.
Do I need to log personal trips too?
You don't need to claim for them, but your total annual mileage (business and personal) supports the business-use percentage if you use the actual expense method.
What if I've been estimating my mileage for years?
Going forward, log every business trip as it happens — a defensible, contemporaneous log from today onward is far stronger than trying to fix historic estimates retroactively.