IRC Section 280: A Tax Potpourri

IRC Section 280 encompasses a collection of Internal Revenue Code provisions that impose limitations on certain business deductions—making it one of the more nuanced areas of federal tax law. Key subsections include 280A, governing home office and vacation home deduction rules; 280C, which coordinates business expense deductions with employment tax credits to prevent double benefit; 280E, which denies deductions for businesses trafficking controlled substances under federal law; and 280F, which limits depreciation deductions for luxury vehicles and listed property. Understanding these provisions is critical for tax professionals and business owners because the limitations can significantly affect taxable income calculations—especially in industries subject to 280E or businesses with substantial vehicle or home office expenses. Staying current with IRS guidance, court decisions, and legislative changes affecting these provisions is essential to accurate tax reporting, compliance, and effective long-term tax planning strategies.

IRC Section 280A establishes the rules governing deductions for business use of a home, making it one of the most frequently litigated and misunderstood tax code provisions. Under 280A, a taxpayer may deduct home office expenses only if a portion of the home is used regularly and exclusively for business—as a principal place of business, a client meeting place, or a separate structure used in the trade or business. The regular and exclusive use standard is strictly interpreted: a space used for both work and personal activities generally does not qualify. Allowable deductions can include a proportionate share of rent or mortgage interest, utilities, insurance, and depreciation. The deduction is generally limited to gross income from the business activity, preventing home office deductions from creating a net loss. The simplified method—allowing a flat rate per square foot—offers an alternative to the complex allocation calculation method for qualifying taxpayers seeking a straightforward approach.

IRC Section 280E is among the most consequential and controversial provisions in federal tax law for cannabis businesses. Enacted in 1982 following a court case where a drug trafficker claimed business expense deductions, 280E prohibits any deduction or credit for expenses incurred in a trade or business consisting of trafficking in Schedule I or II controlled substances. Because cannabis remains a Schedule I substance under federal law—despite legalization in many states—cannabis businesses cannot deduct ordinary operating expenses like payroll, rent, marketing, or professional fees. The only allowable deduction is Cost of Goods Sold (COGS), which includes direct costs of producing or acquiring inventory. This creates effective tax rates far exceeding those of comparable legal-industry businesses—sometimes exceeding 70% of gross profit. Legislative proposals to reschedule cannabis from Schedule I to Schedule III could significantly change the 280E landscape, making this a critical area for cannabis industry tax professionals to monitor.

IRC Section 280F imposes annual depreciation caps on passenger automobiles and listed property—assets with potential for significant personal use—used in a trade or business. For passenger cars, annual depreciation deductions are limited regardless of the vehicle's actual cost, with specific dollar caps updated annually by the IRS for inflation. These limitations apply to both general MACRS depreciation and bonus depreciation under Section 168(k), meaning even vehicles eligible for first-year expensing face capped deductions if they are passenger automobiles. Heavy SUVs exceeding 6,000 pounds GVWR are partially exempt from the luxury caps but face a separate Section 179 expensing limitation. Listed property also includes items like cameras and recording equipment that blend business and personal use, which require contemporaneous recordkeeping of business-use percentage. Understanding 280F is essential for tax professionals advising clients on vehicle purchases, fleet management, and business asset depreciation planning strategies.

IRC Section 280C is a coordination rule preventing taxpayers from receiving a double tax benefit when claiming certain employment-related tax credits. Specifically, 280C reduces the deductible wage expense by the amount of wages used to calculate credits such as the Work Opportunity Tax Credit (WOTC) and the Research and Experimentation Credit. The rationale is that if wages generate a tax credit—which directly reduces tax liability—allowing the same wages as a full deduction would provide a benefit Congress did not intend. For businesses claiming these credits, the effective net benefit of 280C coordination must be modeled carefully. Taxpayers may elect to claim a reduced credit rate, which bypasses the wage expense reduction, or accept the full credit with the corresponding reduction in deductible wages. The optimal choice depends on the taxpayer's marginal tax rate: higher-rate taxpayers may prefer the full credit with the wage reduction, while lower-rate taxpayers might prefer the reduced credit election. Tax professionals must run both scenarios to determine which approach minimizes overall tax liability.