How to Write Off a Truck for Business: Section 179 and Bonus

To write off a truck for business, the fastest path is a combination of Section 179 expensing and 100% bonus depreciation, which together can deduct the full purchase price in year one if the truck’s gross vehicle weight rating tops 6,000 pounds and you use it more than half the time for business. For 2026, Section 179 is capped at $32,000 for heavy SUVs but runs up to $2,560,000 for qualifying pickups with longer beds, and the One, Big, Beautiful Bill permanently restored 100% bonus depreciation on qualified property acquired after January 19, 2025.¹² Trucks under 6,000 pounds still qualify for a deduction, but strict annual caps stretch the write-off over several years.

Start With the Weight Rating

The gross vehicle weight rating, or GVWR, is the single number that decides which set of rules applies to you. It appears on a label inside the driver’s side door jamb and in the owner’s manual, and it represents the maximum loaded weight the manufacturer assigns to the vehicle. Trucks rated above 6,000 pounds but not above 14,000 pounds fall outside the IRS definition of a “passenger automobile,” which is what lets them escape the tight annual depreciation caps that apply to lighter vehicles.³

Most full-size pickups clear 6,000 pounds. So do full-size SUVs, commercial vans, and cargo vans. Mid-size trucks and crossover SUVs usually do not. If you are buying with the deduction in mind, check the GVWR before signing. A rating of 5,900 pounds versus 6,100 pounds can shift the first-year deduction on an identical purchase price by tens of thousands of dollars.

You Must Use the Truck More Than Half the Time for Business

The IRS will not let you expense a truck aggressively unless you use it more than 50% for business during the year you place it in service.³ Fall to 50% or below and you lose access to both Section 179 and bonus depreciation, leaving straight-line depreciation over five years as your only option.⁴

Your deduction is also proportional. A truck used 80% for business produces 80% of the available deduction. Track the percentage from the first day the truck is in service, and keep records to back it up. Commuting between your home and a regular office does not count as business use.

Section 179: The Immediate Expense Election

Section 179 lets you deduct the cost of qualifying business property in the year you buy it rather than spreading the deduction over several years. For any four-wheeled vehicle designed primarily to carry passengers, rated between 6,001 and 14,000 pounds GVWR, the 2026 Section 179 deduction is capped at $32,000.¹ That cap covers most heavy SUVs and many crew-cab pickups with short beds.

Some work-oriented trucks escape the $32,000 cap entirely and can be expensed up to the general 2026 Section 179 limit of $2,560,000. The exceptions include:

Pickup trucks and vans with a cargo area at least six feet long that is open or enclosed by a cap, and not easily accessible from the passenger compartment.
Vehicles designed to seat more than nine passengers behind the driver’s seat.
Vehicles with no seating behind the driver and a fully enclosed driver and cargo area, with no body section extending more than 30 inches ahead of the windshield.

A contractor’s standard eight-foot-bed pickup, for example, is not subject to the $32,000 cap and can be fully expensed under Section 179 in the year of purchase.⁵

Section 179 has one constraint bonus depreciation does not: your deduction cannot exceed your total taxable income from all active trades or businesses for the year. If the deduction would push business income below zero, the excess carries forward rather than creating a loss on this year’s return. That matters if your business had a thin year or you are buying late in the year before revenue materializes.

100% Bonus Depreciation Is Back

The One, Big, Beautiful Bill, signed into law in 2025, permanently restored 100% first-year bonus depreciation for qualified property acquired after January 19, 2025.² The earlier phase-down (80% in 2023, 60% in 2024, 40% for early 2025) no longer applies to trucks purchased after that date.

Bonus depreciation applies to whatever cost remains after your Section 179 deduction, and at 100% it wipes out the remaining balance in year one. Unlike Section 179, bonus depreciation has no dollar cap for vehicles over 6,000 pounds and no taxable income limitation. It can generate a net operating loss that you carry to other tax years.

The 100% rate applies to both new and used trucks, as long as the vehicle was not previously used by the same taxpayer. A used truck from a dealer or another business qualifies just as a factory-fresh one does, provided you acquired it after January 19, 2025.

If you expect significantly higher income next year, front-loading the whole deduction now may waste it at a lower bracket. The law allows an election of a reduced 40% bonus depreciation rate for qualified property placed in service during your first tax year ending after January 19, 2025, and you can also elect out of bonus depreciation entirely and depreciate the truck over five years using MACRS.²

A Worked Example

Say you buy an $80,000 heavy SUV in 2026 with a GVWR of 7,200 pounds and use it 100% for business. The SUV has a short cargo area, so the $32,000 Section 179 cap applies.

Section 179: $32,000
Remaining basis after Section 179: $48,000
100% bonus depreciation on the remaining basis: $48,000
Total first-year deduction: $80,000

The entire purchase price is written off in year one. At 80% business use instead of 100%, every figure above is multiplied by 0.80, producing a $64,000 deduction.

Now take the same $80,000 truck with an eight-foot bed. Because the bed exceeds six feet, the $32,000 Section 179 cap does not apply. You could take the full $80,000 as a Section 179 deduction alone, or skip Section 179 and claim 100% bonus depreciation on the entire amount. Either route produces a full write-off in year one.

If Your Truck Is 6,000 Pounds or Less

Trucks and SUVs with a GVWR of 6,000 pounds or less are classified as passenger automobiles, and the IRS imposes strict annual depreciation ceilings regardless of what you paid.³ For a vehicle placed in service in 2026 with bonus depreciation claimed, the caps are:

Year 1: $20,300
Year 2: $19,800
Year 3: $11,900
Year 4 and beyond: $7,160 per year until the cost is fully recovered

If you elect out of bonus depreciation, the first-year cap drops to $12,300; the later years stay the same. These limits apply to the combined total of Section 179, bonus, and regular MACRS depreciation. A $55,000 mid-size truck at 6,000 pounds GVWR takes roughly six years to fully depreciate under these caps. A 6,500-pound version of the same truck can be written off in one.

Actual Expenses or the Standard Mileage Rate

The IRS offers two ways to deduct vehicle costs: the standard mileage rate (72.5 cents per mile for 2026) or actual expenses, which cover fuel, insurance, repairs, registration, and depreciation.⁶ The choice interacts directly with a truck write-off.

Here is the trap. If you claim Section 179 or bonus depreciation on your truck, you are locked into the actual expense method for the life of that vehicle. You cannot switch to the standard mileage rate later.⁷ For an expensive heavy truck, the actual expense method almost always wins anyway, especially in year one. But if you drive few business miles and your operating costs are low, run both methods before filing. The Section 179 or bonus election is irreversible for this vehicle.

What Changes If You Lease

Leasing takes Section 179 and bonus depreciation off the table because you do not own the truck. Instead, you deduct the business-use portion of your lease payments as an operating expense under the actual expense method.⁷ If you choose the standard mileage rate for a leased vehicle, you must use it for the entire lease term, including renewals.

For leased passenger vehicles at or under 6,000 pounds GVWR with a fair market value above $62,000, the IRS requires you to add a small “lease inclusion amount” to your income each year, preventing lessees from sidestepping the luxury auto caps. The amounts are published annually and increase modestly with the vehicle’s value and each successive lease year. For heavy trucks above 6,000 pounds that fall outside the passenger automobile definition, the lease inclusion rules generally do not apply.

Records the IRS Will Accept

The IRS requires contemporaneous records for vehicle expenses, meaning you document trips at or near the time they happen. A log updated weekly qualifies as timely.³ Reconstructing a year of mileage the night before your tax appointment is how deductions get disallowed.

For each business trip, log four things: the date, the destination, the business purpose, and the miles driven. Also record the odometer at the start and end of each year, and total miles driven (business and personal combined) so the IRS can verify your business-use percentage.³ A GPS-based smartphone mileage app satisfies these requirements and is more reliable than a paper notebook.

If you use the actual expense method, keep receipts for fuel, oil changes, tires, insurance, tolls, parking, and repairs. You do not need to log every gas station stop, but you need enough documentation to reconstruct the total cost of operating the truck for the year.

Recapture: When the Deduction Comes Back

A large first-year deduction is not permanent by itself. Two events can force some of it back into your taxable income.

Business Use Drops to 50% or Less

If you claimed Section 179 or bonus depreciation and business use later falls to 50% or below during the truck’s five-year recovery period, you must recapture the excess depreciation. The excess is the difference between what you deducted using accelerated methods and what you would have deducted under straight-line. That difference is added to your income as ordinary income in the year the drop occurs.⁸ The rule runs through the end of the recovery period, not just the year after purchase.

Selling or Trading In the Truck

When you sell a business truck, gain is taxed as ordinary income up to the total depreciation previously claimed. If you bought a truck for $80,000, wrote off the entire amount in year one, and later sold it for $35,000, the full $35,000 is ordinary income, not capital gain.⁹ Only gain in excess of total depreciation taken would qualify for capital gains rates, which rarely happens with a depreciating vehicle.

Trade-ins no longer get tax-free like-kind exchange treatment. Since the Tax Cuts and Jobs Act took effect in 2018, Section 1031 exchanges are limited to real property.¹⁰ Trading your old truck for a new one is treated as selling the old and buying the new: recognize gain or loss on the disposition and start fresh depreciation on the replacement.

Your State May Not Follow Along

Federal rules are only half the picture. Many states decouple from federal bonus depreciation entirely, and others impose their own lower Section 179 caps ranging roughly from $25,000 to $500,000. A truck that produces an $80,000 federal write-off might yield only a fraction of that on your state return. Check your state’s conformity rules before assuming the federal deduction carries through, and be ready to keep a separate depreciation schedule for state purposes if it does not.

1
Internal Revenue Service. Rev. Proc. 2025-32
2
Internal Revenue Service. Treasury, IRS Issue Guidance on the Additional First Year Depreciation Deduction Amended as Part of the One, Big, Beautiful Bill
3
Internal Revenue Service. Publication 463 (2025), Travel, Gift, and Car Expenses
4
Internal Revenue Service. Publication 946 (2025), How To Depreciate Property
5
Office of the Law Revision Counsel. 26 USC 179 – Election to Expense Certain Depreciable Business Assets
6
Internal Revenue Service. IRS Sets 2026 Business Standard Mileage Rate at 72.5 Cents per Mile, Up 2.5 Cents
7
Internal Revenue Service. Topic No. 510, Business Use of Car
8
Internal Revenue Service. Instructions for Form 4562 (2025)
9
Internal Revenue Service. Publication 544 (2025), Sales and Other Dispositions of Assets
10
Internal Revenue Service. Like-Kind Exchanges – Real Estate Tax Tips