Franchised Dealership Taxes: Floor Plan Interest, the LIFO Reserve, Demo Cars for the Sales Staff, and the Real Estate the Factory Wants You to Own

A franchised dealership is three businesses under one roof — new and used vehicle sales, finance and insurance, and service and parts — financed by a floor plan that charges interest on every car on the lot. The tax issues follow that structure: how the floor plan interest is deducted, how a lot full of inventory is valued, what the sales staff's demonstrators cost in payroll tax, when finance income is recognized, and how the building the manufacturer requires is depreciated.

Floor plan interest and the interest limit

Floor plan financing — the line of credit secured by vehicle inventory — generates interest that is deductible, but the business interest limit under Section 163(j) treats it specially: floor plan interest is deductible without limit, and a dealer that relies on that exception to deduct interest above the general 30 percent cap gives up bonus depreciation on property placed in service that year. Dealers under the gross receipts threshold ($32 million of average annual gross receipts for 2026) are exempt from the limit entirely and keep bonus depreciation. For larger dealers, the trade-off each year is between unlimited floor plan interest and 100 percent bonus on the facility improvements and equipment — and because the 2025 law restored the depreciation add-back to adjusted taxable income for tax years beginning after 2024, more dealers' interest now fits under the 30 percent cap without the exception, so the calculation is worth running before year-end purchases.

Inventory and LIFO

New vehicle inventory is the dealership's largest asset and its largest tax lever. Many franchised dealers use the LIFO method — treating the most recently acquired vehicles as sold first — which in years of rising invoice prices defers tax by building a LIFO reserve. The alternative LIFO method and the inventory price index method simplify the computation for vehicle dealers. The reserve reverses when inventory shrinks: a year of low allocations or a model-line discontinuation can recapture years of deferral into one taxable year, and a dealer that converts from a C corporation to an S corporation must include the LIFO reserve (the LIFO recapture amount) in income in its last C corporation year, with the resulting tax payable in four annual installments. Used vehicles are typically valued at the lower of cost or market, with market taken from an industry guide's average wholesale value; demonstrators remain inventory — by definition a demonstrator is a vehicle currently in the dealer's inventory and available for customer test drives — and loaners are inventory only while held for sale rather than placed in service.

Demonstrators and the sales staff

A demonstrator provided to a full-time salesperson for use in selling, with personal use limited by a written policy, is a working condition fringe benefit excluded from the salesperson's wages under the qualified automobile demonstration use rules. The IRS simplified full inclusion method sets a daily includable amount for employees who are not full-time salespeople — office staff and service managers, for example — based on the vehicle's value under the annual lease value table, reported on the W-2. Dealers who provide vehicles without a policy or without tracking who drives what face payroll tax on the full value of the use in an audit; demonstrator policies are a standard examination item.

Finance and insurance income

Finance reserve — the dealer's share of the interest rate spread paid by the lender — is income when the dealer's right to it is fixed, generally at contract funding, even if the lender holds part of it back in a dealer reserve account. A reserve for future chargebacks when customers pay off early is not deductible; a chargeback is deducted when it is fixed and paid, and the recurring item exception lets an accrual-method dealer deduct a year-end chargeback paid within eight and a half months after year-end. Commissions on extended service contracts, gap coverage, and other products are income when earned; a dealer that is the obligor on its own service contracts reports the price as income under the general timing rules — the advance payment rules defer it no later than the following year — unless it insures its risk and adopts the service warranty income method (Rev. Proc. 97-38), which spreads the income over the contract. Manufacturer holdback, incentives, and floor plan assistance are income when the dealer's right to them becomes fixed.

Service, parts, and the body shop

The service department's labor is income as performed; parts are inventory sold at retail and wholesale; warranty work is billed to the manufacturer and is income when the dealer's right to payment is fixed and the amount can be determined with reasonable accuracy, not when the manufacturer pays. Sublet repairs are pass-through costs. Technician tools provided by the dealer are depreciable; tool allowances paid to technicians are wages unless paid under an accountable plan with substantiation.

The facility and cost segregation

Manufacturer image programs require dealerships to build or renovate to brand standards, and the resulting facilities are large. A cost segregation study separates the showroom's lighting, signage, service equipment, lifts, paving, and site improvements from the 39-year building, moving a meaningful share into 5-, 7-, and 15-year property eligible for bonus depreciation (subject to the floor plan interest trade-off for property the dealership itself owns; a real estate LLC that leases the building to the dealership and has no floor plan debt of its own is not caught by that rule). The real estate is commonly held in a separate LLC leased to the dealership — manufacturers permit it, and it keeps the land out of the operating entity.

Cash, sales tax, and Florida

Any cash payment of more than $10,000 in one transaction or related transactions triggers Form 8300 within 15 days, with penalties for failure that dealers have paid heavily. Florida dealers collect the 6 percent state sales tax on vehicle sales plus the discretionary sales surtax of the buyer's county of residence (applied to the first $5,000 of the price) for Florida residents, apply the trade-in credit, and handle out-of-state buyers under the partial exemption rules; the dealer remits through its sales tax account and is liable for errors. Documentary stamp tax applies to the retail installment contracts.

Worked example. A dealership with $38 million of gross receipts holds $9 million of new vehicle inventory on floor plan and pays $520,000 of floor plan interest. Its receipts exceed the $32 million gross receipts threshold for 2026, so it is within the business interest limit; its total business interest — the $520,000 of floor plan interest plus a small amount of other interest — exceeds 30 percent of its adjusted taxable income, so it deducts the floor plan interest under the exception — and forgoes bonus depreciation on the $1.2 million showroom renovation it paid for and placed in service that year, depreciating it under regular MACRS with a cost segregation study instead. Its LIFO reserve grew $340,000 as invoice prices rose, deferring that much income. Twelve salespeople drive demonstrators under a written policy; three office and service managers' demonstrators are included in their W-2 wages under the full inclusion method. A $14,000 cash down payment triggers Form 8300.

Official sources

The IRS explains: “In all cases, if a dealer receives more than $10,000 in cash, the dealer will be required to file Form 8300, Report of Cash Payments over $10,000 Received in a Trade or Business.” — Internal Revenue Service, Retail Audit Technique Guide (Publication 5495), https://www.irs.gov/pub/irs-pdf/p5495.pdf

The IRS explains: “This revenue procedure provides optional simplified methods for determining the value of the use of demonstration automobiles provided to employees by automobile dealerships.” — Internal Revenue Service, Revenue Procedure 2001-56, https://www.irs.gov/pub/irs-drop/rp-01-56.pdf

The Florida Department of Revenue explains: “The surtax rate that applies to motor vehicles and mobile homes is determined by the home address of the purchaser.” — Florida Department of Revenue, Florida Sales and Use Tax, https://floridarevenue.com/taxes/taxesfees/Pages/sales_tax.aspx

Related guides

• Franchised Dealership Entity and Estimated Taxes: The Factory's Approval of Your Ownership, the LIFO Reserve That Turns, and the Quarter the Incentives Arrive
• Used Car Dealer Taxes: Floor Plan Interest, Form 8300 for Cash Deals, Buy-Here-Pay-Here Installment Sales, and Inventory That Depreciates on the Lot
• Inventory for Tax: FIFO, LIFO, and the Small Business Rule
• Cost Segregation Study: What It Is and When It Pays
• Fringe Benefits Employees Don't Pay Tax On

Next step

Fairlight Accounting handles U.S. domestic, cross-border (U.S.–Canada), and international tax returns, plus bookkeeping, payroll, and CFO advisory. Our U.S. Tax Desk runs the floor plan interest versus bonus depreciation calculation and maintains the LIFO computation each year. See pricing or book a free fit call.