Can I use the flat rate without proof?

Yes, the flat rate is accepted by the tax office without further documentation. However, you should still keep receipts for all vehicle costs — the total needs to be verifiable.

What about electric vehicles?

The same rules apply. For the flat-rate method, add back 0.9% of the purchase price per month. A home charging station is a business asset and can be depreciated.

Correctly calculating private use of a business vehicle

If you use your car for both business and private purposes, you must separate the costs. Here's the correct calculation of the private share — flat rate or logbook method.

2 min read

Why separation is necessary

Costs for a vehicle used both for business and private purposes are only partially tax-deductible. The tax office expects a clear separation — otherwise, the entire vehicle cost is treated as private and not deductible.

Method 1: Flat rate

The simplest method: you deduct all vehicle costs as business expenses and add back a private share of 0.9% of the purchase price (excl. VAT) per month — 10.8% per year, at least CHF 1,800. Example: purchase price CHF 40,000 → private share CHF 4,320 per year. The tax office accepts this without further proof. Keep all receipts (fuel, maintenance, insurance, depreciation).

Method 2: Logbook

If your private use is clearly below the flat rate, a logbook is worth it. Record every trip with date, route, purpose and kilometres. At year-end, calculate the private share exactly. More work, but potentially significant tax savings if your business share is high.

What counts as a business trip?

Trips to clients, to the bank, to the post office for business matters, to suppliers, to training events. The commute to your office generally counts as private — unless your office is identical to your home (home office), in which case trips to clients are the primary business trips.

Accurate as of: The rates and amounts mentioned in this article reflect the state as of 7 August 2026. They are for information only and do not replace tax or legal advice. For binding information, contact the Swiss Federal Tax Administration (ESTV), your cantonal tax office, or a fiduciary.

Frequently asked questions

Can I use the flat rate without proof?: Yes, the flat rate is accepted by the tax office without further documentation. However, you should still keep receipts for all vehicle costs — the total needs to be verifiable.
What about electric vehicles?: The same rules apply. For the flat-rate method, add back 0.9% of the purchase price per month. A home charging station is a business asset and can be depreciated.