Mileage Deduction Mastery: Turning Your Commute Into a Tax Write-Off
At $0.725 per mile in 2026, mileage is likely your single largest tax deduction. But only if you track it right and understand the rules about business vs. commuting miles.
If you're a relief vet and you're not meticulously tracking your mileage, you are leaving money on the table. Not small money. Potentially $10,000-$20,000 in deductions per year.
The IRS standard mileage rate for 2026 is $0.725 per mile. For a relief vet driving 25,000 business miles per year, that's an $18,125 deduction — likely the single largest write-off on your Schedule C.
But the IRS has specific rules about what counts as a "business mile," and getting it wrong can cost you in an audit. Here's everything you need to know.
Standard Mileage Rate vs. Actual Expense Method
You have two choices for deducting vehicle costs. You must pick one, and the choice you make in the first year matters.
Standard Mileage Rate
Multiply your business miles by the IRS rate:
2025: $0.70 per mile
2026: $0.725 per mile
This rate covers gas, insurance, depreciation, maintenance, repairs, and wear on your vehicle. You can deduct parking fees and tolls on top of the standard rate.
Pros:
Simple to calculate
Generous rate — often more than actual costs for economy/midsize vehicles
Less record-keeping (just track miles, not every expense)
Cons:
If you drive an expensive vehicle with high operating costs, actual expenses may be higher
Can't switch to actual expense method later (if you start with actual expenses, you can't switch to standard rate for that vehicle)
Actual Expense Method
Track every vehicle expense, then deduct the business-use percentage:
Gas and oil
Repairs and maintenance
Tires
Insurance premiums
Registration and license plate fees
Depreciation or lease payments
Car washes (if you transport patients or equipment)
Calculate your business-use percentage: (business miles ÷ total miles) × 100
Pros:
Can yield a larger deduction for expensive or high-maintenance vehicles
Cons:
Requires tracking every single vehicle expense with receipts
More complex tax preparation
Must deal with depreciation schedules and recapture
Which Is Better for Relief Vets?
For most relief vets driving a standard car or SUV, the standard mileage rate wins. Here's a quick comparison:
Factor
Standard Rate
Actual Expenses
25,000 miles at $0.725/mile
$18,125
—
Actual costs (gas $3,500 + insurance $1,200 + maintenance $1,500 + depreciation $3,500) × 85% business use
—
$8,245
In this typical scenario, the standard rate gives you more than double the deduction. It's almost always the right choice unless you drive a luxury vehicle.
The Critical Rule: Business Miles vs. Commuting
This is where most relief vets either lose thousands of dollars or gain them.
Without a Home Office
If you don't have a qualifying home office, the IRS treats your first trip of the day (home to first clinic) and your last trip (last clinic to home) as non-deductible commuting — even though you go to different locations every day.
Travel between work sites during the day IS deductible.
Example: You drive from home to Clinic A (20 miles), then Clinic A to Clinic B (15 miles), then Clinic B to home (25 miles).
Deductible: 15 miles (Clinic A to Clinic B only)
Non-deductible commuting: 45 miles (home to A + B to home)
With a Home Office
If you have a qualifying home office (see our article on the home office deduction), your home IS your principal place of business. Every trip is a business trip.
Same example with a home office:
Deductible: 60 miles (all trips)
Non-deductible: 0 miles
Over a year, this difference compounds dramatically. If your average daily "commuting" miles are 40, that's about 10,000 miles per year — worth $7,250 in additional deductions at the 2026 rate.
What the IRS Requires in Your Mileage Log
The IRS requires a contemporaneous record — meaning you record trips at or near the time of travel, not reconstructed from memory at year end. Your log must include:
Date of each trip
Destination (clinic name and city)
Business purpose (e.g., "relief shift at Valley Animal Hospital")
Miles driven for each trip
Odometer reading at the beginning and end of the year
A mileage log created after the fact from calendar entries is technically not compliant, though in practice many CPAs use calendar data as supporting evidence. The gold standard is real-time tracking.
Best Tracking Methods
Mileage Tracking Apps
These automatically detect and log trips using your phone's GPS:
MileIQ — auto-detects trips, swipe to classify as business/personal
Everlance — combines mileage tracking with expense management
Driversnote — popular with contractors, exports IRS-compliant reports
Stride — free, designed for gig workers and freelancers
The key advantage: automated tracking creates the contemporaneous log the IRS requires, with no manual effort beyond classifying each trip.
Manual Tracking
If you prefer not to use an app:
Keep a small notebook in your car
Record the date, destination, purpose, and miles for each trip
Note your odometer reading on January 1 and December 31
ReliefBooks (Coming Soon)
ReliefBooks automatically calculates the distance to each clinic when you log a shift, so your mileage record is built into your shift history. No separate app needed.
Parking and Tolls
Regardless of which method you use (standard rate or actual expenses), you can always deduct parking fees and tolls paid for business travel. These are separate line items on Schedule C.
Keep receipts for parking garages. Toll records from your E-ZPass or SunPass account work as documentation.
Common Mistakes
Not tracking at all. "I'll figure it out at tax time" leads to either a wildly inaccurate estimate (audit risk) or a conservative one (lost money).
Deducting commuting miles without a home office. This is the single most common mileage audit issue for independent contractors.
Using round numbers. Logging exactly 50 miles every day looks suspicious. Track actual miles — they'll vary naturally.
Not keeping the annual odometer reading. The IRS uses beginning and ending odometer readings to cross-check your total mileage claims. Get in the habit of photographing your odometer on January 1.
Forgetting personal trips. If you use the same vehicle for personal and business travel, only business miles are deductible. Your tracking app will ask you to classify each trip.
The Bottom Line
For most relief vets, mileage is the largest deduction available to you. At $0.725 per mile in 2026:
15,000 business miles = $10,875 deduction
25,000 business miles = $18,125 deduction
35,000 business miles = $25,375 deduction
Set up a home office. Use a tracking app. Log every trip. The effort takes minutes per day and saves you thousands per year.
Kal Saad