Company car logbook in Switzerland: when it beats the 0.9 % rule and how to keep it

In Switzerland, private use of a company car is declared on the salary certificate (Lohnausweis / certificat de salaire) in one of two ways: the flat private share of 0.9 % of the purchase price per month, or the actual private kilometres from a logbook (Bordbuch / carnet de bord), multiplied by CHF 0.75. A logbook only pays off for employees who drive little privately, and the tax authorities accept it only if it meets strict formal requirements.

If you are used to the German 1 % rule or to UK benefit-in-kind bands, the Swiss system is simpler on paper but stricter in practice: the logbook must be kept every day, and the commute counts as private. This guide is for expat employees with a company car and for the HR teams who issue salary certificates. It shows the break-even point, what the Swiss Tax Conference (SSK / CSI) requires, how to structure a logbook and why mileage can be captured with no manual entry. That is what Voltaback's box-free telematics does, without the company ever receiving location data.

The essentials in 30 seconds

• Default rule: 0.9 % per month of the purchase price excl. VAT, at least CHF 150.– per month, in box 2.2 of the salary certificate, with field F ticked. The commute is included.
• Alternative: actual private kilometres, commute included, × CHF 0.75. Field F is not ticked.
• Break-even: for a CHF 50'000.– car, the logbook only wins below 600 private km per month, commute included.
• Form: kept daily, complete and without gaps, in a fixed form; in an electronic logbook, later changes must be documented.
• Data protection: the employer needs the total of private kilometres, not the places visited.

Key terms: private share, field F and logbook

A few Swiss terms first, since they appear on every salary certificate:

• Private share (Privatanteil / part privée): the taxable benefit of being allowed to use a company car privately. It is salary in kind and is shown in box 2.2 of the salary certificate.
• Field F: the box for "free transport between home and workplace". When it is ticked, the employee cannot deduct commuting costs in their tax return.
• Logbook: the daily record of trips that proves the actual private kilometres.
• Expense regulations (Spesenreglement / règlement des frais): the company's internal rules on expenses, which can be approved by the tax authority of the canton where the company has its seat.

The default: a 0.9 % private share per month

Where the employer bears all the car's costs and the employee only pays fuel or energy for longer private trips at weekends or on holiday, the private share is calculated as a flat rate:

• 0.9 % per month of the purchase price, including all optional extras, excluding VAT;
• at least CHF 150.– per month, which applies to cars priced below CHF 16'667.–;
• for a leased car, the cash purchase price stated in the lease contract (excl. VAT).

The amount goes in box 2.2 and field F is ticked: the flat rate also covers the commute. The SSK gives the example of a CHF 50'000.– car: CHF 450.– per month, or CHF 5'400.– per year.

If the employee pays the employer for private use, that amount is deducted from the private share (SSK FAQ 2.2.4). Paying only for fuel or charging, however, is not enough to remove it.

The rate is the same for an electric car: the official guidance has no reduced rate by powertrain. Other tax points are covered in our guides to electric company car taxation and to the private share of an electric company car.

Sources: FTA, Guidance on the salary certificate 2026, para. 21 and 22; SSK, Salary certificate FAQ 2026.

The alternative: actual private kilometres from a logbook

Instead of the flat rate, the private share can be declared at its actual value, provided a logbook is kept. The calculation: private kilometres × CHF 0.75. The official guidance gives the example of 8'500 private km × CHF 0.75 = CHF 6'375.–.

Two things change compared with the flat rate:

• The commute counts as private. The SSK FAQ states it plainly: the journey to work is treated as a private trip.
• Field F is not ticked. With the actual method, the cross in field F is dropped (FAQ 2.2.2). The FAQ reserves possible taxation of the commute linked to the cap on the travel cost deduction, so confirm the treatment with your cantonal tax administration.

The logbook is also the route for cross-border commuters whose private use is restricted by the rules of their country of residence: the private share stays at 0.9 % by default (FAQ 2.2.9), but a logbook allows the actual private use to be declared. This is common in Geneva and Basel.

Source: SSK, Salary certificate FAQ 2026, points 2.2.1, 2.2.2, 2.2.8 and 2.2.9.

Break-even: when the logbook beats the flat rate

The logbook is worth it when private kilometres × CHF 0.75 stay below 0.9 % of the purchase price. The monthly break-even:

Break-even (private km per month) = purchase price excl. VAT × 0.9 % ÷ CHF 0.75

Worked example for a CHF 50'000.– car:

1. Flat rate: CHF 50'000.– × 0.9 % = CHF 450.– per month (CHF 5'400.– per year).
2. In kilometres: CHF 450.– ÷ CHF 0.75 = 600 private km per month (7'200 km per year).
3. Below 600 private km per month, commute included, the logbook lowers taxable income. Above it, the flat rate is better.

The commute trap

Take an employee who lives in Baar and works in Zug, 5 km away, with a CHF 50'000.– electric car:

• Commute: 5 km × 2 × 220 working days = 2'200 km per year, about 183 km per month.
• That leaves about 417 km per month for everything else before the logbook stops paying.

An employee who lives in Lausanne and works in Geneva (about 60 km) exceeds the break-even with the commute alone. For them, the flat rate is almost always better.

The logbook suits someone who lives close to the office, often drives straight to clients and rarely uses the car at weekends: for example, a field engineer in Basel whose depot is 3 km from home.

Tip: before choosing, record total and private kilometres for two or three months. The break-even takes two minutes to compute, and the decision then rests on numbers, not impressions.

What the Swiss Tax Conference requires

From the logbook, the tax authority must be able to see how many kilometres were driven privately and how many for business. The SSK FAQ (point 2.2.8) sets three levels.

Mandatory information

General information, for example on the first page:

• the driver;
• the calendar year;
• the odometer reading on 1 January and 31 December.

Daily information, filled in on the day of the trip:

• the date of the trip;
• the person visited, with the place (for example "X AG, Rümlang");
• the number of kilometres driven.

Desirable but optional information

• the time;
• the exact business purpose (for example a client visit);
• a "private trip" note. It is not needed: where no information is given, a trip is assumed to be private.

Mandatory formal requirements

• The logbook must be kept daily, completely and without gaps.
• It must have a fixed form: no loose-leaf ring binders.
• For an electronic logbook, later changes must be documented.

In practice, a spreadsheet filled in at month-end and edited without a trace does not meet these requirements. Source: SSK, Salary certificate FAQ 2026, point 2.2.8.

Mileage log template: the columns

Paper or electronic, a usable logbook holds the same information. Here is the structure with a filled-in example:

On the first page: driver, licence plate, calendar year and the odometer reading on 1 January, then on 31 December at year-end. Time and energy charged are optional columns, but useful for an electric car.

The real difficulty is not the template, it is daily discipline. Someone driving 25'000 km a year fills in several hundred lines, every day, without missing one.

Paper, spreadsheet, app, box or connected car

There are five ways to keep or feed a logbook. They differ in compliance, workload and data protection.

A GPS box removes manual entry but brings location data into the company. Art. 26 of Ordinance 3 to the Labour Act (ArGV 3 / OLT 3) bans systems intended to monitor behaviour, and recording private trips is very hard to justify. Details are in our guide to GPS tracking of company vehicles in Switzerland.

Connected car data gives the soundest base: the odometer reading taken from the car itself, time-stamped, with no entry, for the 1 January and 31 December readings and for monthly tracking.

Data protection: what the employer may see

A logbook holds sensitive data: people visited, places, times and, indirectly, private trips. Art. 328b of the Code of Obligations limits processing to data needed to perform the employment contract. The revised Federal Act on Data Protection (revFADP, nDSG / nLPD) adds proportionality and data protection by design (Arts. 6 and 7).

For the salary certificate, the employer needs one figure: the year's total private kilometres, and therefore total mileage. It does not need to know where the employee spent Saturday.

A sound set-up therefore separates:

• the car's mileage, which the company may receive automatically;
• the trip details, which stay with the employee and are produced only if the tax authority asks.

Sources: Code of Obligations, Art. 328b; revFADP; OLT 3, Art. 26.

Tip: state in your vehicle policy exactly which data reaches the company. The sentence "no location data is passed to the employer" answers most questions from the staff committee.

Setting up reliable mileage capture in four steps

1. Pick the method per employee

Compute each car's break-even and compare it with observed private kilometres. Anyone above it stays on the 0.9 % rule, with no logbook.

2. Write the rules into the vehicle policy

Who keeps the logbook, in what form, and how and when private kilometres are reported to HR. Keep the records with payroll documents: business records must be kept for ten years (Art. 958f CO).

3. Remove manual odometer readings

The reading on 1 January, on 31 December and at each month-end can come straight from the connected car. It is the figure most often forgotten and the first one the tax authority checks.

4. Route the data to the right tools

Mileage feeds fleet management (servicing, lease contracts, CO2) and the driver's app. The management side is covered in our guide to fleet mileage tracking, and lower energy costs in our guide to fleet eco-driving.

What Voltaback changes in practice

• Mileage without entry: each car's odometer reading comes automatically from the connected car, with no box, for more than 48 car brands, electric and combustion (pre-2020 models are sometimes harder to connect).
• No location data for the company: the employer receives mileage, consumption and vehicle data, never employees' positions.
• Driver app: employees see their own kilometres and charging sessions in the driver app.
• Beyond mileage: consumption, eco-driving, alerts and maintenance, plus a monthly export ready to import into your payroll software for charging reimbursement.
• Security: 100 % software, ISO 27001 certified since 2 December 2025, compliant with the revFADP.

The trip details the SSK requires (person visited, place) remain the driver's responsibility. Voltaback supplies the base the tax authority checks first: a reliable, time-stamped odometer reading.

Switch to mileage capture without entry

Odometer readings should no longer depend on drivers' memory. Book a telematics demo: in 30 minutes you see which cars in your fleet can be connected and how mileage arrives with no box and no location tracking.