Yes, you can write off a trailer used for your business, and in most cases you can deduct the entire purchase price in the year you place it in service. The two mechanisms that make this possible are Section 179 expensing and 100% bonus depreciation. How much you actually get to deduct depends on one number above all others: the percentage of the time you use the trailer for business.
The 50% Business Use Rule Controls Your Deduction
A trailer only qualifies as a deductible expense if it’s “ordinary and necessary” for your line of work.1Office of the Law Revision Counsel. 26 U.S.C. 162 – Trade or Business Expenses A flatbed for a contractor clears that bar easily. A boat trailer for an accounting practice does not.
If you split the trailer between work and personal use, only the business portion is deductible. Use it 80% for hauling job-site equipment and 20% for weekend trips, and your deduction is 80% of the cost and 80% of the related expenses.2Internal Revenue Service. Publication 334, Tax Guide for Small Business
Trailers used to transport goods or equipment are generally treated as “listed property” under the tax code.3Office of the Law Revision Counsel. 26 U.S.C. 280F – Limitation on Depreciation for Luxury Automobiles and Listed Property That classification carries a hard threshold. Business use has to exceed 50% in the year you put the trailer into service, or you lose access to both Section 179 and bonus depreciation and are stuck with slower straight-line depreciation.
The threshold doesn’t just matter in year one. If your business use later drops to 50% or below, the IRS claws back part of what you already deducted. This recapture equals the difference between the accelerated depreciation you took and the straight-line amount you would have been entitled to over the same period. A trailer you wrote off in full can become a tax bill later if your usage pattern changes.
Section 179 Expensing
Section 179 lets you deduct the full cost of qualifying business equipment in the year you start using it, instead of spreading the deduction across several years. For the 2026 tax year, the maximum Section 179 deduction is $2,560,000, and it phases out dollar-for-dollar once your total qualifying equipment purchases exceed $4,090,000. Both figures adjust annually for inflation.4Internal Revenue Service. Instructions for Form 4562, Depreciation and Amortization Small businesses buying a single trailer rarely bump into either number.
There is one significant limit. Your Section 179 deduction can’t exceed your total taxable business income for the year.4Internal Revenue Service. Instructions for Form 4562, Depreciation and Amortization If the business nets $30,000 and the trailer cost $40,000, Section 179 gets you $30,000. The remaining $10,000 isn’t lost; it carries forward to future years.5eCFR. 26 CFR 1.179-2 – Limitations on Amount Subject to Section 179 Election The election is claimed on Form 4562.6Internal Revenue Service. About Form 4562, Depreciation and Amortization
100% Bonus Depreciation
Bonus depreciation is a separate first-year write-off. Under the One, Big, Beautiful Bill, 100% bonus depreciation was made permanent for property acquired after January 19, 2025.7Internal Revenue Service. Treasury, IRS Issue Guidance on the Additional First Year Depreciation Deduction Amended as Part of the One, Big, Beautiful Bill Trailers qualify because they’re tangible property with a MACRS recovery period of 20 years or less.8Office of the Law Revision Counsel. 26 U.S.C. 168 – Accelerated Cost Recovery System
Bonus depreciation has two advantages over Section 179. There’s no business income cap, so it can create or deepen a net operating loss. And it covers used property, as long as the trailer is new to you. The trade-off is that bonus depreciation is automatic for a class of property unless you actively elect out for the entire class. You can’t pick and choose which assets in the same recovery period get it.
Combining Section 179 and Bonus Depreciation
For most small businesses, the smart order is Section 179 first, up to the taxable income cap, then bonus depreciation for whatever is left. This matters when your income is smaller than the trailer’s cost.
Say your business earns $25,000 in taxable income and you buy a $35,000 enclosed trailer. Section 179 covers the first $25,000, stopped by the income limit. Bonus depreciation then wipes out the remaining $10,000 and creates a net operating loss you can carry forward. Full write-off in year one, but only if business use exceeds 50%.2Internal Revenue Service. Publication 334, Tax Guide for Small Business
De Minimis Safe Harbor for Inexpensive Trailers
Buying a small utility trailer for a couple thousand dollars? Skip the depreciation machinery altogether. The de minimis safe harbor lets you expense items costing $2,500 or less per invoice as a current-year business expense. Businesses with audited financial statements can use a $5,000 threshold.9Internal Revenue Service. Tangible Property Final Regulations
The election is made annually on the return. For an $1,800 open trailer, this is by far the simplest path: expense it, deduct it, and move on. No Form 4562, no depreciation schedule.
What Goes Into the Cost You Write Off
The deductible amount isn’t just the sticker price. Your cost basis includes sales tax, freight or delivery, and any installation or setup charges.10Internal Revenue Service. Publication 551, Basis of Assets Pay $800 in sales tax and $400 for delivery on a $15,000 trailer, and your depreciable basis is $16,200. These add-ons aren’t separately deductible; they roll into the asset’s cost and come out through whichever write-off method you use.
Ongoing Trailer Expenses You Can Also Deduct
The purchase deduction is only part of it. The day-to-day costs of running a business trailer are deductible as ordinary business expenses, in proportion to your business use percentage.
- Insurance premiums and annual registration fees on the trailer.11Internal Revenue Service. Topic No. 510, Business Use of Car
- Interest on a loan used to finance the trailer. Business equipment loan interest has no annual dollar cap.12Office of the Law Revision Counsel. 26 U.S.C. 163 – Interest
- Routine maintenance and minor repairs like tires, bearings, and brake work, deducted in the year you pay for them.
Bigger spending is treated differently. Work that makes the trailer better than it was, restores it from a non-functional state, or adapts it to a new use has to be capitalized and depreciated rather than deducted right away.9Internal Revenue Service. Tangible Property Final Regulations Replacing brake pads is a repair. Bolting a refrigeration unit onto a flatbed is an improvement.
What Happens When You Sell the Trailer
Selling a trailer you’ve written off creates a tax bill many owners don’t see coming. A trailer is Section 1245 property, so any gain on the sale is taxed as ordinary income up to the total depreciation you claimed.13Internal Revenue Service. Publication 544, Sales and Other Dispositions of Assets
The math is straightforward. Buy a trailer for $20,000, claim a full $20,000 Section 179 deduction, and your adjusted basis is zero. Sell it three years later for $8,000, and the entire $8,000 is ordinary income. No capital gains rate applies to that money because the gain came entirely from depreciation you already took.
Only gain that exceeds total depreciation claimed can be treated as Section 1231 gain and potentially get capital gains treatment.13Internal Revenue Service. Publication 544, Sales and Other Dispositions of Assets Because you rarely sell a used trailer for more than you paid new, nearly all of the sale proceeds on a fully-depreciated trailer will hit as ordinary income. The write-off isn’t free money. It’s a deferral that moves income from the purchase year into the year you dispose of the trailer.
Documentation the IRS Expects
Listed property gets stricter scrutiny than ordinary business expenses, and trailers used for transportation are listed property. You need two kinds of records.
For the purchase itself, keep the invoice, proof of payment, and registration documents showing when the trailer was placed in service. The placed-in-service date fixes which tax year the deduction belongs to, and the IRS will check it if the return is examined.
For ongoing business use, the IRS wants contemporaneous records: logs created at or near the time of each use showing date, destination, business purpose, and duration. Reconstructing this from memory at year-end is the sort of evidence that collapses in an audit. A trailer that lives at a job site and never leaves business use is easier to document, but you still need records establishing the pattern.
Hold onto everything, including depreciation schedules and improvement receipts, until the statute of limitations closes for the year you sell or dispose of the trailer.14Internal Revenue Service. How Long Should I Keep Records? That’s usually three years after filing the return for the disposal year, but it stretches to six or seven if the IRS suspects underreported income. Keeping the paperwork for the full ownership period plus six years after sale is the safest habit.