Car expense reports: how to log business trips and what to keep for the tax office

Two situations, one habit

There are two very different reasons to keep car expenses:

• Your employer reimburses you for trips made with your own vehicle or for costs advanced on the road (tolls, parking, hotel).
• You claim actual expenses on your French income-tax return, because you believe your professional costs exceed the automatic 10 % deduction.

The rules differ, but the habit that makes both painless is the same: write it down when it happens. Reconstructing a month of trips from memory in April is where mistakes and refused claims come from.

What to log for every trip

A useful trip record is short. For each professional trip:

1. The date.
2. The purpose — who or what you went for, in a few words.
3. Where — departure and destination.
4. The distance driven.
5. One receipt per expense: fuel, tolls, parking, hotel, meals.

Group the receipts by trip, not by type. A month of "fuel" is hard to defend; "Lyon client visit, 14 March: 412 km, two tolls, one parking, one lunch" is a story anyone can check.

What the tax rules say (France, employees)

According to the official service-public.gouv.fr page on flat deduction versus actual expenses:

• Employees are entitled to an automatic 10 % flat deduction for professional expenses.
• If your real expenses are higher, you can opt for actual expenses, individually within a couple.
• Covered costs include home–work travel, professional trips, meals, training and, where justified, remote work or a second residence.
• For car travel, an official mileage scale is used to value the trips; an online simulator is provided.
• The receipts must be kept and made available to the tax authorities for 3 years. You don't attach them to the return, but you must declare the total with a breakdown.

This is general information, not tax advice: rules differ for self-employed people and can change each year. Check the official page and, if in doubt, ask an accountant.

Keeping receipts without a shoebox

Thermal-paper receipts fade within months, and the ones you need are always the ones that vanished. The habit that works: photograph the receipt the moment you get it, and attach it to the trip.

Autofy has an expense-report function built for this: photograph fuel, toll, parking, hotel and meal receipts, group them by trip, and export a PDF ready for your accountant or employer. Expense reports and their PDF export are free, like the maintenance log and health score for one vehicle; Autofy+ adds spending insights (cost per km, 12-month trend, spreadsheet export).

While you're at it, keep the same discipline for your service invoices: they are what makes a car worth more when you sell it.

Source: Service Public — Frais professionnels : forfait ou frais réels.

Frequently asked questions

How long must I keep receipts for actual expenses in France? The official page says you must keep them and make them available to the tax authorities for 3 years. You keep them; you don't attach them to your tax return.

What is the difference between the flat deduction and actual expenses? Employees get an automatic 10 % deduction for professional expenses. If they think their real expenses are higher, they can opt for actual expenses and must then be able to justify each one.

What should a trip log contain? The date, the purpose of the trip, where you went and the distance driven, then one receipt per expense: fuel, tolls, parking, hotel, meals.

Where can I find the official mileage scale? Through the mileage-allowance scale and simulator referenced on the official service-public.gouv.fr page on actual expenses, which is updated each year.