Mileage Reimbursement vs Fuel Cards: Which Is Better?

A fuel card pays for fuel. The IRS mileage rate pays for fuel plus depreciation, insurance, maintenance, tires and registration. That is why running both against the same miles is not generous, it is a duplicate payment, and the overlap is taxable wages. Choosing between them is really a choice about who absorbs the cost of the vehicle itself.

Sources: Treas. Reg. 26 CFR 1.62-2; IRS Publication 463; IRS Internal Revenue Bulletin 2026-29.

What each one actually covers

• Fuel card: fuel only. The driver still absorbs depreciation, insurance, maintenance, tires and registration on a vehicle being worn out for the employer's benefit.
• Mileage reimbursement at the IRS rate: all vehicle operating costs, fuel included. For the second half of 2026 that is 76 cents per mile, against 72.5 cents for the first half.

Fuel is typically a minority of the true per-mile cost of running a vehicle. A fuel card that feels generous at the pump can still leave a driver meaningfully out of pocket over a year of heavy mileage.

You cannot run both for the same miles tax-free

Because the standard rate already includes fuel, paying a driver the full rate and handing them a fuel card reimburses fuel twice. The fuel card value is not covered by the accountable-plan exclusion for the mileage that has already been reimbursed at the full rate, so it becomes taxable compensation.

Employers who want both usually structure it as a reduced cents-per-mile rate alongside the card, so the combined payment approximates but does not exceed the operating cost. That requires the same substantiation as any accountable plan: date, destination, business purpose and miles.

Personal use is where fuel cards go wrong

A fuel card is a payment instrument, not a per-trip expense. If a driver fills up on a Sunday for personal driving, that fuel has no business connection and fails the first test of an accountable plan. The value is taxable wages.

Keeping it tax-free means substantiating card spend against business mileage, which means the employer needs the mileage log anyway. The administrative saving people expect from a fuel card largely disappears once compliance is included.

Comparing the two on the same driver

A field technician drives 22,000 business miles in the second half of 2026 in a vehicle averaging 28 miles per gallon, with fuel at $3.40 a gallon.

• Fuel card value: 786 gallons at $3.40 is about $2,672.
• Mileage reimbursement at 76 cents: $16,720.
• Gap the driver absorbs under the fuel card: roughly $14,000 of depreciation, insurance, maintenance and tires.

That gap is the reason fuel-card-only arrangements generate turnover among high-mileage staff, and it is the exposure behind expense-indemnification claims in California, Illinois and Massachusetts, where employers carry a statutory duty to cover necessary business expenses. Our state breakdown sets out where that applies.

When a fuel card genuinely makes sense

• The vehicle is company-owned, so the employer already bears depreciation and insurance
• Fleet fuel purchasing discounts and consolidated reporting outweigh the reimbursement admin
• Drivers never use the vehicle personally, or personal use is separately valued as a fringe benefit

For a personal vehicle used for work, mileage reimbursement under an accountable plan is the simpler and more defensible arrangement. It is tax-free to the employee, deductible to the employer, and requires one record rather than two.

Can an employee deduct the shortfall if the fuel card is all they get?

Federally, no. Unreimbursed employee business expenses remain suspended. The remedy is a better reimbursement policy, not a filing position. See deducting mileage after reimbursement.

What about a fuel card plus a flat car allowance?

A flat allowance paid regardless of miles driven has no business connection to a documented expense and is taxable in full, and the card sits on top of it. This is the least tax-efficient combination in common use. See is a car allowance taxable.

Does the employer have to use the IRS rate?

No. The rate is a ceiling for tax-free treatment, not a floor for what has to be paid. Anything above it is wages. Anything below it is permitted federally, subject to state expense-indemnification law.

Both arrangements need the same thing underneath: a defensible record of business miles. TruMile produces it automatically, so substantiation is a monthly export rather than a reconstruction. Try TruMile →

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