A car allowance is a flat monthly payment added to your paycheck and taxed like salary; mileage reimbursement pays a per-mile rate for actual business trips and stays tax-free when it’s at or below the IRS standard rate. That’s the heart of the car allowance vs. mileage reimbursement question, and for 2026 the IRS rate is 72.5 cents per mile.1Internal Revenue Service. IRS Sets 2026 Business Standard Mileage Rate at 72.5 Cents Per Mile, Up 2.5 Cents For most drivers, the tax treatment is what decides which option leaves more money in your pocket.
What a Car Allowance Actually Pays You
A car allowance is a fixed sum, usually paid monthly or biweekly, added to your regular paycheck. The amount doesn’t change whether you drive ten miles or a thousand. It’s meant to cover fuel, insurance, maintenance, and depreciation in one flat figure.
Because the payment isn’t tied to documented expenses, the IRS treats a standard car allowance as a non-accountable plan. The full amount shows up on your W-2 and is subject to federal income tax, Social Security, and Medicare, the same as wages.2Internal Revenue Service. Rev. Rul. 2005-52
The math is uncomfortable. If your marginal federal rate is 22% and you add the 7.65% employee share of payroll taxes, roughly 30% of the allowance is gone before you spend a dollar on gas. A $600 monthly car allowance nets closer to $420.
A car allowance can be structured to avoid tax, but only if the employer builds it as an accountable plan: employees log trips, substantiate expenses, and return anything unspent.3eCFR. 26 CFR 1.62-2 – Reimbursements and Other Expense Allowance Arrangements At that point it’s a mileage reimbursement program wearing a different name, and most employers who offer a flat allowance do so precisely to skip that paperwork.
Why Mileage Reimbursement Stays Tax-Free
When your employer reimburses you at or below the IRS standard rate and you substantiate the trips, the entire reimbursement is excluded from your gross income.4Internal Revenue Service. Notice 2026-10 – 2026 Standard Mileage Rates It doesn’t show up on your W-2. No federal income tax, no Social Security, no Medicare.
The 72.5-cent figure comes from an annual IRS study of what it costs to own and operate a car, bundling fuel, depreciation, insurance, and maintenance into one number. An employer can pay less than the IRS rate, which is legal but may not cover your real costs. An employer can also pay more, in which case only the excess is taxable. If your company reimburses at 80 cents per mile and you drive 500 business miles, you receive $400; the 7.5 cents above the IRS rate, $37.50, is reported as taxable wages, and the remaining $362.50 stays tax-free.5Internal Revenue Service. Rev. Proc. 2019-46
The rule sits on a simple premise in the tax code: reimbursement replaces money you spent doing your job, not money that made you richer.6Office of the Law Revision Counsel. 26 U.S. Code 162 – Trade or Business Expenses Prove the miles, and the IRS treats you as whole rather than ahead.
You Can No Longer Deduct the Difference
Before 2018, an employee stuck with a taxable car allowance had a partial rescue on the personal return: unreimbursed business vehicle expenses could be claimed as a miscellaneous itemized deduction subject to a 2% floor of adjusted gross income. The Tax Cuts and Jobs Act suspended that deduction, and federal law now permanently eliminates miscellaneous itemized deductions, including the write-off for unreimbursed employee business expenses.7Office of the Law Revision Counsel. 26 USC 67 – 2-Percent Floor on Miscellaneous Itemized Deductions
The consequence is direct. If your employer gives you a taxable car allowance and your real driving costs exceed what you netted after taxes, you eat the difference. There’s no personal deduction to close the gap. With mileage reimbursement, every documented business mile is covered tax-free and no gap opens in the first place.
Which One Leaves You With More Money
The answer depends on how many business miles you drive and how consistent that driving is.
High or consistent mileage. Mileage reimbursement almost always wins. At 72.5 cents per mile, 1,500 business miles a month is $1,087.50, all of it tax-free. A car allowance would need to be about $1,550 before tax to net the same amount at a typical withholding rate.
Low or unpredictable mileage. A car allowance is predictable, but the tax bite makes it inefficient dollar for dollar. Per-mile reimbursement still delivers more value, though the amounts may be small enough that a flat allowance’s simplicity feels worth the loss.
Varied driving across regions. Neither a flat allowance nor a single per-mile rate fits a workforce whose fuel and insurance costs differ by geography. A FAVR plan, described below, is designed for that case.
FAVR: The Hybrid Option
A Fixed and Variable Rate plan splits the reimbursement in two. The fixed component covers costs that don’t change with mileage, such as depreciation, insurance, and registration. The variable component covers per-mile costs like fuel and maintenance. Structured correctly, the entire FAVR payment is tax-free.
FAVR addresses a real weakness of a single per-mile rate: it overpays high-mileage drivers, whose fixed costs spread across more miles, and underpays low-mileage drivers, whose fixed costs loom larger per mile. By separating the two categories, FAVR keeps payments closer to each employee’s actual expenses.
The IRS imposes strict eligibility rules. Each employee must drive at least 5,000 business miles per year, or 80% of the plan’s projected annual business mileage, whichever is greater. The plan’s baseline vehicle price cannot exceed a cap the IRS updates each year, set at $61,700 for 2026. Your own vehicle must have cost at least 90% of that baseline price, and it can’t be older than the plan’s retention period, which is at least two years.5Internal Revenue Service. Rev. Proc. 2019-46 Miss any of these, and part or all of the reimbursement becomes taxable.
What Counts as a Business Mile
Not every mile you drive for work is a business mile, and getting this wrong is one of the fastest ways to lose the tax-free treatment. The IRS is clear: driving between home and your regular workplace is commuting, and commuting is never deductible or reimbursable on a tax-free basis.8Internal Revenue Service. Publication 463 (2025), Travel, Gift, and Car Expenses
Business mileage starts once you leave your first work location for a second, or when you drive from your regular office to a client. Trips from home to a temporary work site also count as business miles, provided you have a regular place of work elsewhere. If your home is your principal place of business, trips from home to any other work location in the same trade qualify as business miles regardless of whether the destination is temporary or permanent.8Internal Revenue Service. Publication 463 (2025), Travel, Gift, and Car Expenses
In practical terms: home office to client site is business. Home to corporate office is commuting; corporate office to client is business.
What You Have to Document
Tax-free treatment lives and dies by your records. The tax code requires you to substantiate every business trip with the amount, the time and place of travel, and the business purpose.9Office of the Law Revision Counsel. 26 U.S. Code 274 – Disallowance of Certain Entertainment, Etc., Expenses For each trip, that means the date, starting point, destination, miles driven, and reason for the trip.
The IRS expects the log to be created at or near the time of the trip. A year-end reconstruction from memory won’t hold up. A GPS-based smartphone app that captures trips automatically is the common solution, but a consistent written log works too. If you can’t produce records, the IRS can reclassify the entire reimbursement as taxable wages.5Internal Revenue Service. Rev. Proc. 2019-46
Is Your Employer Required to Reimburse You?
Federal law does not generally require employers to reimburse employees who use a personal car for work. The Fair Labor Standards Act sets one floor: if unreimbursed vehicle expenses push your effective hourly pay below the federal minimum wage, that’s an FLSA violation.10eCFR. 29 CFR 531.35 This mainly protects lower-wage employees who drive heavily, like delivery drivers and home health aides.
Roughly a dozen states go further and require employers to reimburse necessary business expenses regardless of wage level. California and Illinois have the broadest requirements. Massachusetts, Montana, New Hampshire, Iowa, New York, North Dakota, and South Dakota also impose some form of mandatory reimbursement. None of these states set a specific per-mile rate; the standard is that the reimbursement be reasonable and cover actual costs. If you drive for work in one of these states and get nothing, that’s worth looking into.