Mileage and Vehicle Deductions: Rules Business Owners Miss

Your vehicle is probably one of your biggest business deductions, and it is also one of the first places the IRS looks when it reviews a small business return. The reason is simple: cars are used for both business and personal driving, and the line between the two is easy to blur. When the records are thin, an auditor can disallow the entire deduction, not just the part that looks questionable.

Let me repeat that…. When the records are thin, an auditor can disallow the entire deduction, not just the part that looks questionable.

The good news is that the rules are not complicated once you know them. Most of the problems we see in our practice come from a handful of misunderstandings: counting commuting miles, skipping the mileage log, picking the wrong method in year one, or buying a heavy SUV without understanding the strings attached.

This year adds a new wrinkle. For the first time since 2022, the IRS changed the business mileage rate in the middle of the year, which means your 2026 mileage log needs to be split in two. Below we walk through the rules business owners miss most often, and what to do about them before December 31.

Two methods, one important first-year choice

The IRS gives you two ways to deduct the business use of a vehicle.

The standard mileage rate. You multiply your business miles by a rate the IRS sets. The rate is meant to cover gas, insurance, repairs, maintenance and depreciation. You can still deduct business parking and tolls on top of it, and if you are self-employed, the business share of interest on your car loan.

The actual expense method. You add up what the vehicle really cost you during the year (fuel, oil changes, tires, repairs, insurance, registration, lease payments or depreciation, and loan interest) and deduct the business-use percentage. If you drove 20,000 miles and 14,000 were for business, you deduct 70% of those costs.

The 2026 rate changed on July 1

In December 2025 the IRS set the 2026 business rate at 72.5 cents per mile. Then, citing higher fuel costs, it raised the rate to 76 cents per mile for driving on or after July 1, 2026, in Announcement 2026-11. The medical and military moving rate also rose, from 20.5 to 23.5 cents. The charitable rate is fixed by law at 14 cents.

Purpose	Jan 1 – Jun 30, 2026	Jul 1 – Dec 31, 2026
Business	72.5¢ per mile	76¢ per mile
Medical / qualified military moving	20.5¢ per mile	23.5¢ per mile
Charitable	14¢ per mile	14¢ per mile

That means you cannot simply total your 2026 business miles and multiply by one number. Here is how the split works for a business owner who drove 18,000 business miles:

8,000 miles from January through June × $0.725 = $5,800
10,000 miles from July through December × $0.76 = $7,600
Total 2026 deduction: $13,400

Applying 76 cents to all 18,000 miles would overstate the deduction by $280, and that is exactly the kind of error that draws a notice. If your log is organized by date, the split is easy. If it is not, now is the time to fix it.

The year-one rule most people never hear about

If you want the option of using the standard mileage rate, you must use it in the first year the vehicle is placed in service for business. After that you can switch to actual expenses in a later year if it works out better. But if you start with actual expenses and claim accelerated depreciation, you are locked out of the standard rate for that vehicle for good.

Leased vehicles have their own rule. If you choose the standard mileage rate for a leased car, you must use it for the entire lease, including renewals.

The standard rate is also off the table if you operate five or more vehicles at the same time, or if you have already claimed Section 179, bonus depreciation, or MACRS depreciation on the vehicle.

Which method is better?

There is no universal answer, but some patterns hold:

High mileage, economical car: the standard rate usually wins.
Expensive vehicle, moderate mileage: actual expenses, especially with depreciation, often win.
Heavy truck or SUV purchased for the business: actual expenses with Section 179 or bonus depreciation can produce a very large first-year deduction (more on that below).

We run the numbers both ways for clients in the first year, because that decision shapes every year after it.

Commuting miles are never business miles

This is the most common mistake we see. Driving from your home to your regular place of business, and back, is commuting. It is a personal expense, no matter how far you drive, and no matter whether you take work calls or haul supplies along the way. Putting a company logo on the car does not change that either.

What does count as business driving:

Driving from your office or shop to a client, customer, supplier, or job site
Driving between two work locations during the day
Trips to the bank, post office, or office supply store for the business
Driving to a temporary work location (generally one expected to last a year or less)
Travel to meetings, trainings, and business events away from your regular workplace

When your home office changes the picture

If your home office qualifies as your principal place of business, the trip from home to your first business stop of the day is generally a business trip, not a commute. That can turn thousands of personal miles into deductible ones.

To qualify, the office has to be used regularly and exclusively for business, and it has to be where you handle the administrative and management work of the business, with no other fixed location where you do that work. A desk in the corner of the guest room that also hosts the family computer will not pass.

If you have a separate office or shop that you go to every day, the home office generally does not convert that drive into business miles, even if you also do some work at home.

Mixed-purpose trips

Stopping at a client’s office on the way to the grocery store does not make the whole trip business. Count only the miles that were added for the business stop, or the leg that was genuinely for business. Auditors are trained to look for logs where every trip ends at home and every trip is labeled “client meeting.”

No log, no deduction

Vehicles fall under the strictest recordkeeping rules in the tax code. Section 274(d) requires you to substantiate business use with adequate records made at or near the time of the trip. Estimates written up the following April do not meet that standard, and courts routinely uphold the IRS when it disallows a vehicle deduction entirely because the log was reconstructed or missing.

For each business trip, your record should show:

The date of the trip
The starting point and destination
The business purpose (“Site visit – Smith kitchen remodel,” not “business”)
The miles driven

You should also record the odometer reading at the start and end of the year, so total miles and business miles can be compared.

Practical ways to stay compliant

Use an app. GPS mileage apps record trips automatically and let you tag them as business or personal with a swipe. This is the easiest way to keep a contemporaneous log.
Keep a notebook in the car if you prefer paper. Fill it in at the end of each day, not the end of the year.
Use your calendar as backup. Appointments in your calendar support the business purpose of trips in your log.
Keep receipts for fuel, repairs, insurance, and registration if you use actual expenses, and for parking and tolls under either method.

For 2026 specifically, make sure your records clearly separate miles driven before July 1 from miles driven on or after July 1, since they are deducted at different rates.

If you are reading this in the fall and realize you do not have a log, start one today. A complete log for the last few months of the year, combined with calendars, invoices, and receipts for the earlier months, is far stronger than nothing at all.

Buying a vehicle before year-end? Read this first

The One Big Beautiful Bill Act made 100% bonus depreciation permanent for qualifying property acquired after January 19, 2025, and raised the Section 179 expensing limit to $2.56 million for 2026. For the right vehicle, that can mean deducting most or all of the purchase price in the year you buy it. But the rules depend heavily on the vehicle’s weight and how you use it.

Passenger vehicles (6,000 lbs GVWR or less)

Cars, small SUVs, and light trucks are subject to annual “luxury auto” depreciation caps. Even with bonus depreciation, first-year depreciation on these vehicles is limited to a set dollar amount, and the rest is spread over several years. Buying a $70,000 sedan for the business will not produce a $70,000 deduction.

Heavy SUVs (more than 6,000 and up to 14,000 lbs GVWR)

This is the category behind the popular “heavy SUV write-off.” The luxury caps do not apply. Section 179 expensing on these vehicles is capped at $32,000 for 2026, but 100% bonus depreciation can cover the rest of the cost.

Example: a business owner buys an $80,000 SUV with a 7,000-lb GVWR and uses it 100% for business. Section 179 covers $32,000, and bonus depreciation covers the remaining $48,000, for an $80,000 first-year deduction.

Pickups with a cargo bed of at least six feet, cargo vans with no seating behind the driver, and certain specialty vehicles are not subject to the SUV cap at all.

The weight that matters is the gross vehicle weight rating (GVWR) printed on the sticker inside the driver’s door, not the curb weight. Check it before you sign.

The strings attached

More than 50% business use is required. If business use is 50% or less, Section 179 and bonus depreciation are not allowed, and you are limited to slower straight-line depreciation.
Only the business share counts. If you use the SUV 75% for business, only 75% of the cost is eligible.
Recapture. If business use drops to 50% or below in a later year, part of the deduction you already took is added back to your income. Selling the vehicle can also trigger recapture.
It must be placed in service by December 31. Signing a purchase agreement is not enough. The vehicle must be delivered and ready for business use in 2026.
Cash flow still matters. A large deduction is only valuable if you have income to offset it. Buying a vehicle you do not need to save tax rarely makes financial sense.
Texas has no state income tax, so the benefit here is federal only. Business owners with income in other states should check how their state treats bonus depreciation.

Your business structure changes the rules

Who owns the vehicle, and what kind of entity you operate, determine where and how the deduction is claimed.

Sole proprietors and single-member LLCs

This is the simplest case. You claim vehicle expenses on Schedule C, using either the standard mileage rate or actual expenses. If you are self-employed, the business share of interest on your auto loan is deductible too.

S corporation owners

This is where we see the most money left on the table. If you own an S corporation and drive your personal car for the business, you are an employee of your corporation, and unreimbursed employee expenses are not deductible on your personal return. That rule was made permanent in 2025.

The fix is an accountable plan: a written reimbursement policy under which you submit your mileage log to the company, and the company reimburses you. Done correctly, the corporation deducts the reimbursement and you receive it tax-free. Without the plan, the deduction is simply lost.

If instead the S corporation owns the vehicle, any personal use by you is a taxable fringe benefit that should be valued and added to your W-2. Skipping that step is a common audit adjustment.

Partners and multi-member LLCs

Partners can sometimes deduct vehicle costs they pay personally as unreimbursed partnership expenses, but generally only if the partnership agreement requires partners to pay those costs themselves. Reimbursement through the partnership is usually cleaner.

W-2 employees

Employees cannot deduct unreimbursed vehicle expenses on their federal return. If you drive for your employer, ask whether the company will reimburse you under an accountable plan. Reimbursements at or below the IRS rate under such a plan are not taxable.

The new car loan interest deduction is personal, not business

The 2025 tax law created a deduction of up to $10,000 per year for interest on a loan used to buy a new personal-use vehicle whose final assembly occurred in the United States, for tax years 2025 through 2028. It phases out for higher incomes. This is a separate break for personal vehicles. Interest on the business portion of a vehicle is deducted as a business expense, and the same dollar of interest cannot be claimed twice.

Quick checklist: the mistakes we fix most often

Deducting the daily drive from home to the office or shop
Using one mileage rate for all of 2026 instead of splitting at July 1
Rebuilding a mileage log from memory at tax time
Claiming 100% business use on the only vehicle in the household
Choosing actual expenses in year one and losing the option of the standard rate forever
Buying a heavy SUV in December without checking the GVWR or the 50% business-use rule
S corporation owners deducting mileage on their personal return instead of using an accountable plan
Forgetting to deduct business parking and tolls on top of the standard rate

Common questions about vehicle deductions

Can I deduct mileage if I take the standard deduction? If you are self-employed, yes. Business vehicle expenses are deducted on your business schedule (Schedule C for most sole proprietors), which is separate from the choice between itemizing and the standard deduction.

I didn’t track my miles this year. Is it too late? Start a log today. For earlier months, rebuild your business trips as carefully as you can from calendars, invoices, client records, and receipts. A reconstructed record is weaker than a contemporaneous log, but it is far better than an estimate with nothing behind it.

Do I need to keep gas receipts if I use the standard mileage rate? No. The rate already covers fuel. You do need your mileage log, and you should keep receipts for business parking and tolls, which are deducted separately.

Can I deduct my car payment? Not the loan principal. Under the actual expense method you recover the vehicle’s cost through depreciation instead. If you lease, the business share of your lease payments is deductible under the actual expense method. Self-employed owners can also deduct the business share of auto loan interest.

Is driving to the bank or post office for my business deductible? Yes, when the trip is for the business and starts from your business location (or from a home office that is your principal place of business).

Does the standard mileage rate apply to electric vehicles? Yes. The same rate applies regardless of fuel type. If you use the actual expense method, the cost of charging for business driving is part of your actual costs.

What if my spouse and I both use the same car for business? Each business that uses the vehicle needs its own records. Keep separate logs so the business miles are not counted twice.

What happens when I sell a vehicle I’ve deducted? Part of every standard mileage deduction counts as depreciation (35 cents of the 72.5-cent rate in early 2026), which lowers your tax basis. If you used actual expenses with Section 179 or bonus depreciation, some of the sale price may be taxed as recaptured depreciation. Talk to us before you trade in or sell a business vehicle.

Can I switch from actual expenses back to the standard rate? Only if you used the standard rate in the vehicle’s first business year and haven’t claimed accelerated depreciation. Otherwise you stay with actual expenses for that vehicle.

Let’s get your vehicle deduction right

Vehicle deductions reward business owners who plan ahead and keep good records, and they punish those who guess. If you are thinking about buying a vehicle before year-end, are not sure which method to use, or run your business through an S corporation without an accountable plan, now is the time to talk. We handle tax preparation, bookkeeping, and IRS representation, so we can help you set it up correctly and stand behind it if the IRS ever asks.

LP Tax And Bookkeeping Pros LLC, McKinney, TX 75072
Phone: 303-881-9762
Email: ralphp@lptaxandbookkeepingpros.com
Web: www.lptaxandbookkeepingpros.com

This article is for general information only and is not tax or legal advice for your specific situation. Tax rules change, and the right answer depends on your facts. Please contact us before acting on anything here.

Sources

Crest Capital: Section 179 and vehicles over 6,000 lbs (2026)

(303) 881-9762