IRS Aviation Tax Rules: Depreciation, SIFL, and Audit Triggers

The IRS aviation tax rules treat a business aircraft as “listed property,” which means every deduction you claim for depreciation, fuel, maintenance, or crew costs depends on two things: proving the plane is used more than half the time for qualified business purposes, and keeping flight-by-flight records detailed enough to defend under audit.¹²³

The Two Business-Use Tests You Must Clear

Before any accelerated depreciation, bonus depreciation, or Section 179 deduction is on the table, the aircraft has to pass two separate tests.

The first is the predominant-use test: more than 50% of the aircraft’s total use for the year must be qualified business use, meaning flights directly connected to your trade or business. Commuting, personal travel, and entertainment flights do not count.¹

The second test, under Section 280F(d)(6)(C)(ii), prevents an owner from satisfying the 50% threshold mostly through their own personal-convenience flights. At least 25% of total use must be qualified business use that does not involve flights by a 5%-or-greater owner or anyone related to such an owner.⁴ An owner-flown jet effectively needs a meaningful amount of rank-and-file employee use.

Fail either test and the aircraft gets pushed onto the slower Alternative Depreciation System for the life of the asset, with recapture of any excess depreciation claimed in earlier years.¹

Writing Off the Purchase Price

Three cost-recovery options sit on top of the business-use tests. Which fits best depends on purchase price, how fast you want to recover cost, and how you want future deductions to look.

100% Bonus Depreciation

The One Big Beautiful Bill Act of 2025 permanently restored 100% bonus depreciation for qualified property, including new and used aircraft, acquired and placed in service after January 19, 2025. For an aircraft placed in service in a 2026 tax year, you can deduct the entire cost basis in year one. If you prefer to spread deductions, you can elect a reduced 60% first-year allowance for aircraft and other long-production-period property.⁵ The deduction is reported on Form 4562.

Section 179 Expensing

As an alternative, you can elect Section 179 and expense up to $2,560,000 of the aircraft’s cost for tax years beginning in 2026. The ceiling phases out dollar-for-dollar once qualifying property placed in service during the year exceeds $4,090,000.⁶ Section 179 lets you take a partial first-year write-off while preserving future depreciation, but it cannot be stacked on top of bonus depreciation on the same dollar of cost.

MACRS or ADS

Without bonus or Section 179, a noncommercial aircraft depreciates under MACRS over a five-year recovery period using a declining-balance method, and you deduct only the business-use percentage. An aircraft used 80% for business produces a deduction equal to 80% of that year’s calculated depreciation. If business use drops to 50% or below in any year, the aircraft moves to ADS over six years on the straight-line method, and prior accelerated deductions are recaptured.¹

Operating Costs and the Entertainment Problem

Fuel, maintenance, hangar fees, insurance, and crew salaries are deductible as ordinary and necessary business expenses under Section 162, allocated by the aircraft’s documented business-use percentage.⁷ If 70% of flights are qualified business flights, 70% of operating costs are deductible. Each leg has to be categorized, and vague logs give the IRS room to reclassify ambiguous legs as personal.

The entertainment rule is where owners most often lose deductions they thought were safe. Since the Tax Cuts and Jobs Act took effect in 2018, no deduction is allowed for expenses tied to entertainment, amusement, or recreation.⁸ A flight to take clients to a game or resort is entertainment, and the allocable operating costs are nondeductible no matter how much business was discussed in the air.

One exception survives. If the company treats the value of the entertainment flight as taxable compensation to the passenger, the expense becomes deductible to the extent reported as wages.⁸ For most employees, that means a full deduction when the W-2 reporting is done correctly. But for “specified individuals” (officers and directors subject to SEC Section 16(a) reporting), the deduction is capped at the amount actually included in compensation. When the real operating cost of a flight dwarfs the SIFL-based income reported on an executive’s W-2, the gap is permanently nondeductible.

Personal Flights as Taxable Fringe Benefits

When an employee flies on the company aircraft for personal reasons, the company must put a value on that benefit, include it in W-2 wages, and withhold accordingly. Doing this correctly also protects the operating-cost deduction under the compensation exception above.

The SIFL Method

The Standard Industry Fare Level formula is the most common valuation method. It combines a flat terminal charge with a mileage calculation across three distance tiers (up to 500 miles, 501 to 1,500, and over 1,500), with per-mile rates that decline as flights get longer. The mileage component is then multiplied by an “aircraft multiple” tied to the plane’s maximum certified takeoff weight and the passenger’s status. For control employees the multiples run from 62.5% on aircraft of 6,000 pounds or less to 400% on aircraft over 25,000 pounds; for non-control employees the range is 15.6% to 31.3%.⁹ On a large-cabin jet, the imputed income for a control employee can be many times what the same flight would produce for a non-control passenger.

Who Is a Control Employee

For 2026, a control employee of a nongovernment employer is a board-appointed or shareholder-elected officer earning $145,000 or more, any employee earning $290,000 or more, anyone with a 1% or greater ownership interest, or a director.¹⁰ An employer can instead elect to use the highly compensated employee definition: a 5% owner at any point during the current or prior year, or anyone earning more than $160,000 in the preceding year.

When the Benefit Is Zero

A non-control employee on a personal flight owes no taxable benefit if at least half the passengers on that flight are traveling for the employer’s business. The exception does not apply to control employees.⁹

Fair Market Value as an Alternative

An employer can skip SIFL and value a personal flight at fair market value, essentially the charter rate for the same route on a comparable aircraft. Fair market value is required when SIFL doesn’t apply, such as when the passenger isn’t traveling as an employee. Once you elect SIFL, you have to apply it consistently to all employees going forward.⁹

Federal Aviation Excise Taxes

Separate from income tax, aircraft operations carry federal excise taxes on fuel, passenger transportation, and cargo, reported quarterly on Form 720.¹¹ Aviation gasoline is taxed at 19.4 cents per gallon and jet fuel used in noncommercial aviation at 21.9 cents per gallon, plus 0.1 cent per gallon for the Leaking Underground Storage Tank Trust Fund. Commercial operators pay a lower jet fuel rate of 4.4 cents per gallon. The fuel supplier usually collects these at the pump, so most operators see them embedded in fuel bills.

The passenger ticket tax is 7.5% of amounts paid for domestic air transportation, plus a per-segment fee of $5.30 for each domestic leg in 2026.¹² Air cargo is taxed at 6.25% of the amount charged. These passenger and cargo taxes fall on commercial operators (charter companies and airlines) that collect them from customers. A company flying its own employees on its own aircraft typically owes only the fuel taxes.

Ownership Structure Traps

The Flight Department Company Problem

Owners often park an aircraft in a separate entity for liability or financing reasons. If that entity’s only business is operating the aircraft, the FAA treats it as a commercial operator, even if it serves only its parent company. Operating without a Part 135 commercial certificate is illegal and carries FAA fines of $11,000 or more per violation along with possible pilot certificate revocation.

The tax exposure is just as serious. The IRS may argue that capital contributions from the parent to the flight-department entity are payments for air transportation, triggering the 7.5% passenger excise tax on every dollar contributed. Insurance carriers may invoke “commercial purpose” exclusions and lenders may call loans on compliance covenants. The safer approach is to give any entity holding an aircraft a genuine business purpose beyond operating the plane, or keep the aircraft on the operating company’s own books.

Passive Activity Limits When You Lease the Plane

Lease the aircraft to others and the income and losses generally fall under the passive activity rules. Rental activities are passive regardless of participation, so losses can’t offset active business income or wages. An exception exists where the average rental period is seven days or less, but you still have to show material participation to use the losses against nonpassive income.

Material participation generally means more than 500 hours per year on the activity, or more than 100 hours if no one else participates more than you. Contemporaneous logs covering scheduling, maintenance oversight, and marketing are essential. The Tax Court has consistently rejected material participation claims built on estimates or reconstructed records.

What Triggers an Audit

Aircraft deductions are a high-priority IRS examination area, and the burden of proof sits entirely with the taxpayer. Every flight should carry a log entry showing date, departure and arrival airports, distance, flight time, all passengers by name, and the specific business purpose for each leg. “Client meeting” is not enough; “meeting with CFO of Acme Corp regarding Q3 supply contract” is. Maintenance records and fuel receipts should tie back to the flight log, and the IRS will cross-reference passenger manifests against W-2 reporting to confirm personal flights produced the right imputed income.

Deadhead legs (repositioning flights with no passengers) take on the character of the leg they support.¹³ Flying empty to pick up executives for a business trip is a business leg; flying empty home after dropping the CEO at a vacation spot is personal. The log has to show the connection clearly, because the IRS will assume the deadhead carries the same passenger count as its associated flight.

Common triggers include a high ratio of owner or family flights to total use, mismatches between the company’s deduction claims and the W-2 income reported for passengers who flew personally, and the absence of a written, enforced aircraft use policy. A clear policy governing who can use the aircraft and when is the single strongest piece of evidence that the plane is a business tool rather than a personal perk. On a multimillion-dollar aircraft, the 20%, 40%, and 75% penalty tiers translate into very large dollar numbers, with interest running from the original due date of the return.

1
Internal Revenue Service. Publication 946 (2025), How To Depreciate Property
2
Office of the Law Revision Counsel. 26 USC 6662 – Imposition of Accuracy-Related Penalty on Underpayments
3
Office of the Law Revision Counsel. 26 USC 6663 – Imposition of Fraud Penalty
4
Office of the Law Revision Counsel. 26 USC 280F – Limitation on Depreciation for Luxury Automobiles; Limitation Where Certain Property Used for Personal Purposes
5
Internal Revenue Service. 2025 Instructions for Form 4562
6
Internal Revenue Service. Revenue Procedure 2025-32
7
Office of the Law Revision Counsel. 26 USC 162 – Trade or Business Expenses
8
Office of the Law Revision Counsel. 26 USC 274 – Disallowance of Certain Entertainment, Etc., Expenses
9
eCFR. 26 CFR 1.61-21 – Taxation of Fringe Benefits
10
Internal Revenue Service. Publication 15-B, Employer’s Tax Guide to Fringe Benefits
11
Internal Revenue Service. Instructions for Form 720 (12/2025)
12
Federal Aviation Administration. Trust Fund Excise Taxes Structure
13
Internal Revenue Service. Allocation Method of Personal Use of Aircraft