Business Vehicle Depreciation

How it works

A vehicle used in a trade or business is deductible as an ordinary and necessary expense under Section 162(a), and I choose one of two methods for each vehicle separately. The standard mileage rate and the actual expense method are compared in practical detail in my business vehicle tax deduction guide; what belongs here is the mechanism inside the actual expense method that can turn an ordinary vehicle purchase into a full write-off in its first year, and the places where that mechanism gives out.

The lever is depreciation. A vehicle used in business is five-year property under the Modified Accelerated Cost Recovery System, and it is also listed property, which means the tax code gates how much of that depreciation is available by how much of the vehicle's use is business rather than personal. For an ordinary passenger vehicle, the code goes further and caps the dollar amount of depreciation allowed in any single year, regardless of what the vehicle actually cost.

Whether that cap applies at all turns on a weight figure, and which figure depends on what the vehicle is. Section 280F(d)(5)(A)(ii) defines a passenger automobile by unloaded gross vehicle weight of 6,000 pounds or less. Section 280F(d)(5)(B) then substitutes plain gross vehicle weight, the manufacturer's GVWR, in the case of a truck or van. So for the vehicles this page is mostly about, the heavy SUV, the full-size pickup, the cargo van, GVWR over 6,000 pounds is the right test and the vehicle steps outside the annual caps entirely. For a passenger car it is not. A large sedan or EV can carry a GVWR above 6,000 pounds while its unloaded weight sits below the line, and that car remains a passenger automobile subject to the caps.

The weight line is not a workaround anyone invented. It is where the statute draws the definition of a passenger automobile, and which side of 6,000 pounds a vehicle sits on decides which depreciation regime applies to it.

A heavy SUV runs into its own separate dollar ceiling on the Section 179 portion of the deduction, narrower than the general expensing limit and built specifically for that subclass. That ceiling does not block a full write-off in year one: bonus depreciation reaches whatever basis the Section 179 ceiling left behind, with no cap of its own for a vehicle over 6,000 pounds, so the SUV's remaining cost is still fully recovered. A qualifying pickup with a long cargo bed, or a cargo van with no passenger seating behind the driver, is not subject to that SUV-specific ceiling at all, and reaches the same full write-off through Section 179, bonus depreciation, or a combination of the two. Bonus depreciation is currently set at 100 percent for qualifying property, vehicles included, acquired and placed in service after January 19, 2025, a rate Congress made permanent rather than the phased-down schedule that applied to purchases made before that date. Where the weight test is met, that combination is what turns a large vehicle purchase into a complete write-off in year one rather than a recovery spread over several years.

For an S corporation owner, I generally keep the vehicle titled in the owner's own name rather than the company's, and recover its cost through an accountable-plan reimbursement instead of a direct deduction on the entity's return. I cover that structure in full in my accountable plan strategy; the short version is that the owner submits an expense report, mileage or a documented business-use percentage of actual costs, the S corporation reimburses it, and that vehicle-cost figure gets used once, through the reimbursement, not claimed a second time as a separate write-off elsewhere on the return.

What this is worth in Florida

Everything above is a federal mechanism, and that matters here because Florida has no individual income tax and does not tax S corporation income at the shareholder level. Nothing about the weight test or the depreciation caps changes a Florida return in a way it would not already change a federal one; the entire benefit runs through the federal side. Florida does apply sales and use tax to the purchase itself, and that tax becomes part of the vehicle's depreciable basis rather than a deduction of its own. There is no Florida add-back or decoupling from section 179 or section 168(k) for a pass-through owner. I go through how Florida treats depreciation more broadly in my Florida depreciation rules guide.

Who this applies to

The gate is Section 162 itself: the vehicle has to be used in carrying on a trade or business, which reaches a Schedule C or Schedule F filer and a rental, partnership, or S corporation activity. Commuting is never deductible under any of this, no matter how many business calls happen along the way. The trip between home and a regular place of work is personal by regulation, not by degree, and no amount of business purpose during the drive changes that.

• The activity. Any trade or business that genuinely puts a vehicle to work: a sole proprietorship, a farm, a rental activity, a partnership, or an S corporation.
• The vehicle. Any car, SUV, van, or truck actually used in that business. Its weight changes how much depreciation is available; it never changes whether the vehicle qualifies for a deduction at all.
• Who this does not reach. A commute, however long, and personal use, however incidental to a business day. Both stay nondeductible regardless of the method chosen or the vehicle involved.

How the deduction actually reaches the return depends on which of those owners is asking. A self-employed filer on Schedule C takes it directly, choosing standard mileage or actual expenses for each vehicle. An S corporation owner generally does not deduct the vehicle personally at all; the entity reimburses the owner through the accountable-plan structure described above, and the deduction lands on the entity's return instead.

What it requires

Three separate thresholds decide what a given vehicle can actually claim, and each one is a cliff rather than a slope.

• More than 50 percent qualified business use. That threshold, a documented majority in fact rather than merely in spirit, is what opens the door to Section 179, bonus depreciation, or accelerated MACRS on the vehicle at all. At 50 percent or below, the law forces the slower straight-line alternative depreciation system, and Section 179 and bonus are both off the table for that vehicle regardless of its weight.
• The standard-mileage election, made in the right year. Electing standard mileage in the first year a vehicle is placed in service preserves the ability to switch to actual expenses, on a straight-line basis, in a later year. Choosing actual expenses with depreciation in year one runs the other way: it forecloses standard mileage on that vehicle for as long as it is owned. A leased vehicle on standard mileage has to stay on it for the entire lease term, including renewals, and the method is not available at all once five or more vehicles are in use at the same time.
• The heavy-vehicle weight test, proven from the right document. Clearing 6,000 pounds GVWR takes a vehicle out of the passenger-automobile definition altogether. Within that heavier category, an SUV rated between 6,001 and 14,000 pounds runs into its own dollar ceiling under Section 179(b)(5), one that a pickup with a cargo bed of six feet or more that is not readily accessible from the cab, a vehicle designed to seat more than nine passengers behind the driver's seat, or a cargo van with no seating behind the driver and no body section protruding more than 30 inches ahead of the leading edge of the windshield, is not subject to at all. Both of those last two are worth reading exactly: the seating test is more than nine, so ten, not nine; and the van test allows up to 30 inches of body ahead of the windshield rather than none, which is what makes it a test an actual van can satisfy.

Miss any one of these and the numbers move against the vehicle: below 50 percent business use, straight-line only; the wrong election in year one, locked out of standard mileage for good; at or under 6,000 pounds, boxed into the passenger-auto caps no matter the price paid.

What you need to document

Every piece of this deduction stands or falls on records built as the year happens, not reconstructed afterward.

A contemporaneous mileage log

Date, business purpose, destination, and miles for every trip. Vehicle expenses fall under the heightened substantiation standard in Section 274(d), and the rule that lets a court estimate other business expenses from credible testimony does not reach this category. No log means no deduction, even when the underlying expense was completely real.

The GVWR rating itself

For a truck or van, the gross vehicle weight rating from the manufacturer's door-jamb sticker, not a figure pulled from a listing site or a sales brochure. For a passenger car, the figure the statute asks for is unloaded gross vehicle weight instead, which is the curb-weight measure rather than the rating plate. A vehicle sitting at exactly 6,000 pounds has not cleared the threshold; the statute is written as 6,000 pounds or less.

Support for the business-use percentage

The same mileage log is what proves the business-use percentage that decides whether Section 179, bonus depreciation, and accelerated MACRS are available at all, and whether any of it has to be repaid later if that percentage falls.

The written accountable plan, for an S-corp owner

A plan meeting all three requirements in the regulation: a business connection to the expense, substantiation within a reasonable time, and return of any excess advance within a reasonable time, backed by the expense reports the owner actually submits and the reimbursements the company actually pays.

Where it goes wrong

This deduction is mainstream, statutorily authorized depreciation. It is not a listed or reportable transaction, and it is not aggressive on its face. The risk sits entirely in an overstated business-use percentage and a missing log, rather than in the structure.

The substantiation cliff

Because vehicle expenses sit under Section 274(d)'s heightened substantiation standard, the ordinary rule that lets an examiner or a court estimate an incomplete business expense from otherwise credible evidence does not apply to this category. A log rebuilt after the fact, even an honest one, does not satisfy the requirement, and the deduction can be disallowed in full even when nobody doubts the vehicle was actually used for business. A log that shows the same round business-use number year after year, exactly 90 percent every time, invites the scrutiny that a real log full of ordinary variation does not.

The recurring mistakes

• Business use slips to 50 percent or below. In the year the vehicle is placed in service, that alone removes Section 179, bonus depreciation, and accelerated MACRS from consideration. In a later year, after accelerated depreciation was already claimed, dropping to that level triggers recapture: the excess already deducted comes back into income under Section 280F(b)(2).
• Commuting gets dressed up as business driving. The trip from home to a regular office stays personal no matter how many calls happen along the way. A home office that is genuinely the principal place of business can convert the first and last trip of the day into deductible mileage; one that exists mainly on paper cannot.
• The two methods get mixed on one vehicle. Separate depreciation, lease payments, fuel, or repairs cannot be added on top of the standard mileage rate for the same vehicle in the same year. Loan interest, the state or local personal property tax attributable to business use, and business-related parking fees and tolls may be added on top of it.
• Section 179 gets stretched past what the business earned. Section 179 cannot create or increase a loss, so any excess simply carries forward. Bonus depreciation carries no such limit and can create a loss outright, which makes the order the two are claimed in matter when income is thin.
• An S-corp reimbursement skips the paperwork. Reimbursing an owner's vehicle costs without the written plan, without real substantiation, or without returning any excess advance turns the entire payment into ordinary W-2 wages, fully subject to payroll tax, instead of a tax-free reimbursement.
• The S corporation titles a vehicle the owner also drives personally. A corporate-owned vehicle with any personal use requires including a fringe-benefit value, figured under the lease-value or cents-per-mile rules, on the owner's W-2. Skipping that inclusion is a straightforward exam adjustment, which is exactly why I keep the vehicle titled to the owner instead.

A situation where this comes up

The version I see most often is a contractor or a tradesperson replacing a work truck, already buying something heavy enough to clear the 6,000-pound line without having planned around the tax code at all. Nothing about the purchase has to change for the mechanism to apply. The real work is confirming the door-jamb rating, starting the mileage log on day one, and keeping the business-use percentage real and documented rather than assumed.

For an S-corp owner in that position, the extra step is making sure the truck is titled personally and reimbursed through the accountable plan, rather than bought in the company's name because that felt simpler at the dealership. That one choice, made in an afternoon, is the difference between a clean reimbursement and a vehicle sitting on the corporate books that generates a fringe-benefit problem for as long as it is owned.

The version that worries me is the vehicle bought first and the business-use percentage decided afterward, at filing time, to make the numbers work. That ordering shows up in the file as a round, unchanging percentage with no log behind it. A missing log means the deduction is disallowed even where the expense was entirely real, which makes it the single biggest source of exam losses on this deduction.