"The Odometer Read What When You Left the House?"
That question, from an accountant preparing a Schedule C, is the one that doesn't have an answer if you didn't write it down the morning of each service call. The IRS mileage deduction requires contemporaneous records — log entries made at or near the time of each trip, not reconstructed from memory at tax time from a Google Maps estimate of the route you probably took six months ago.
This template is the contemporaneous record. Three odometer fields, logged before and after each call, while you're still in the vehicle.
Three Odometer Readings and Why All Three Matter
Start Odometer is read before leaving home or the office. Arrival Odometer is read when you pull into the client's location. Finish Odometer is read at the end of the service call, before departure — the template doesn't actually calculate return miles, but the Finish reading anchors the total vehicle use for the day's record.
Total Miles is calculated automatically: Arrival Odometer minus Start Odometer. This is the door-to-door distance for the trip out. Total Commuting Miles is the user-entered deduction: the IRS treats the home-to-primary-workplace commute as personal, not business. If you work from a company office and then drive to a client site, the home-to-office leg is commuting; office-to-client is business. Total Business Miles is the calculated difference: Total Miles minus Total Commuting Miles. That's the number that goes into the deduction.
Business Miles Reimbursement calculates at $0.211 per business mile — a historical rate hardcoded into the template's formula. The IRS standard mileage rate changes annually (it was $0.67 in 2024); anyone using this template for active expense reimbursement needs to verify the current rate and update the calculation script accordingly. At $0.211, the formula underestimates reimbursement by a significant margin against current rates. The structure of the calculation is sound; the constant needs updating.
Task Number and Time Fields: The Service Record Layer
Task # links the mileage record to the work order, ticket, or service task system. Without it, the mileage log is a standalone record with no way to cross-reference which calls drove which mileage. With it, a monthly mileage summary can be reconciled against the task management system: total mileage for Task #4847 matches what the service ticket shows as the site visit.
Start Time and Arrival Time document drive duration alongside distance. A 23-mile drive that takes 45 minutes is highway driving; one that takes 95 minutes is stop-and-go suburban service territory. That context doesn't affect reimbursement directly, but it affects realistic scheduling for future calls to the same area and is useful when a client asks why a service call required more technician time than expected.
Finish Time marks the end of work at the site. Start to Finish is the total billable window for the call — departure from base through completion of service. For companies billing labor by the hour including travel time, the three time fields together document the full billable period, not just the diagnostic and repair time on-site.
Company Name ties the trip to the client account. Filtering by Company Name across a quarter surfaces every service call made to that client, the total mileage, and the total time — the data for a customer-level utilization review or for building a travel cost component into a service contract renewal negotiation.