Driver’s log (ajopäiväkirja) in Finland: what the Tax Administration requires

Who needs a driver’s log?

Not every driver has to keep a log. It is needed when taxation depends on how the kilometres split between work or business drives and private drives. The usual situations:

• A sole trader drives for the business in their own car. The log shows whether the car belongs to the business or to private use and how large an additional deduction the business drives earn.
• A sole trader’s car belongs to the business. The private kilometres in the log determine the share of car costs that is not deductible.
• An employee makes work trips in their own car. Their evidence is the travel expense claim (matkalasku) on which the employer pays the kilometre allowance.
• An employee has a car benefit (autoetu). A log is needed if the benefit is valued by private kilometres or if a lower taxable value is claimed.
• The owner of a limited company or partnership drives for the company in their own car or uses the company’s car. Trips are shown with a travel expense claim, and private use of the company car is a car benefit.

The log is not attached to the tax return. The Tax Administration asks for it when needed, so it must be kept safe and in order when the request comes – often years after the drives.

Sole trader: the 50 % rule decides where the car belongs

How a sole trader’s car is taxed depends on whether it belongs to the business or to private use. The car belongs to the business when it was acquired for business use and more than 50 % of the kilometres are business drives. If business drives are 50 % or less of the year’s kilometres, the car belongs to private use.

The limit is checked separately for each tax year. The Supreme Administrative Court (KHO 23.1.2012/64) has held that the conditions for the additional deduction are decided on the drives of that tax year; private driving in earlier or later years is irrelevant. The period is the trader’s financial year, and if the business starts mid-year, drives before the start do not count. That is why the Tax Administration advises keeping a log from the very start of the business.

A car owned by your spouse is assessed in the same way as your own. Cars owned by others – for example parents, siblings or a cohabiting partner who is not a spouse for tax purposes – do not qualify for the additional deduction; only actual costs can be deducted. Nor is there an additional deduction for a leased car whose ownership does not pass to the trader, or for a car received from an employer as a car benefit.

Private car: additional deduction for business drives

When a sole trader makes business drives in a car that belongs to private use, they get an additional deduction (lisävähennys) in taxation. It is at most the employee’s tax-free kilometre allowance: up to €0.55/km for kilometres driven in 2026 (€0.59/km for 2025). Car costs already deducted in the books reduce the additional deduction, and if actual costs exceed the maximum, only the actual costs are deducted. Under section 55 of the Business Income Tax Act (EVL), the deduction requires a driver’s log or other reliable evidence of the car’s use and the business trips.

Example: in 2026 the car is driven 20,000 km in total, 6,000 km of it on business. The car belongs to private use and no car costs have been booked. The additional deduction is 6,000 × €0.55 = €3,300. Without the year’s total kilometres no comparison can be made, and no additional deduction is granted.

If someone else, such as the trader’s employee, drives the trader’s car, the additional deduction applies only if the trader – or a spouse running the business together with them – is in the car. Otherwise the trip costs are deducted at actual amounts.

Business car: the private-use share

When the car belongs to the business, the actual car costs and depreciation recorded in the books are deducted. The private share is not deductible: divide the car costs and the annual depreciation by the year’s total kilometres and multiply by the private kilometres in the log. If the private share was deducted in the books, the same amount is added to the business income on the tax return.

Example: car costs €6,000 and depreciation €2,000, €8,000 in total. The car was driven 25,000 km, 5,000 km of it privately. The cost per kilometre is €8,000 / 25,000 km = €0.32, and the private share 5,000 × €0.32 = €1,600. If private drives cannot be shown reliably, their share has to be estimated.

A car acquired for the business does not leave the business assets just because business use temporarily drops below half in one year: whether the car belongs to the business net assets is assessed over more than one year.

Which drives are business drives?

• Drives within the business’s area of operation, such as fetching goods from a warehouse or visiting a customer.
• Drives between the business’s permanent premises.
• Temporary trips outside the business’s usual area of operation.
• A drive from home to your own business premises and back, on the other hand, is private. With several permanent premises, the drive from home to the first premises outside the home and the drive home at the end of the day are private. Home–work trips are deducted as travel expenses in personal taxation.

What goes into a sole trader’s driver’s log?

According to the Tax Administration, the log must show the total kilometres driven in the car during the tax year. For each business drive, record:

• the start and end time of the drive
• the start and end point and, where needed, the route
• the length of the trip
• the purpose of the drive
• the odometer reading at the start and end
• the driver.

The year’s total kilometres are easiest to prove with odometer readings on the first and last day of the year (or financial year). A single entry could look like this: 12.3.2026, 8:10–11:40, office in Vantaa – customer in Espoo – office in Vantaa, 46 km, odometer 48,210 → 48,256, installing equipment for the customer, driver: the trader.

If the same trips are also claimed as a temporary work trip deduction based on per diems, the record must show the destinations, distances and duration day by day, based on actual times. Per diem amounts and conditions are in our guide “Kilometre allowance, per diem and meal allowance in Finland 2026”.

In an example in the Tax Administration’s guidance, a trader claimed the per-diem-based additional deduction (increased living costs on work trips) for 238 days, €12,614 in total (238 × €53, the 2025 full per diem). The log showed only monthly total kilometres, just the name of a city or region for most trips, and no start or end time for any drive, so the duration of the trips could not be shown. The deduction was accepted only for the 88 days whose destinations and routes were recorded in more detail and showed trips lasting over six hours: 88 × €24 = €2,112 at the partial per diem. For 150 days the claim was refused and a tax increase (veronkorotus) was imposed.

Employee using their own car: the travel claim is the evidence

When an employee makes a work trip in their own car, the employer can pay a tax-free kilometre allowance of up to €0.55/km in 2026. The employee’s evidence is not a separate log but the travel expense claim (matkalasku) submitted to the employer. It must show:

• the purpose and destination of the trip (address)
• the route, where needed
• the means of travel
• the start and end dates and times of the trip
• for trips abroad, the country or region where each trip day ended
• for a kilometre allowance, also the kilometres driven and the rate per kilometre.

The claim can also be made in an electronic app if it contains the required details. Many people still keep their own log, which makes the claim easy to put together. If an employee has a full car benefit (vapaa autoetu), no tax-free kilometre allowance can be paid for work drives in that car. A driver of a limited car benefit (käyttöetu) car who pays for the fuel can be reimbursed tax-free for fuel up to €0.11/km. Rate increments, per diems and Incomes Register reporting are covered in our kilometre allowance guide.

Car benefit: private driving and the log

A car benefit (autoetu) arises when an employee or their family uses the employer’s car or van for private driving. Driving between home and work is also private. With a full car benefit (vapaa autoetu) the employer pays all the car’s costs; with a limited car benefit (käyttöetu) the employee pays at least the fuel or charging.

The monthly value of the car benefit assumes 1,500 km of private driving a month, that is 18,000 km a year. The log affects the value as follows:

• Per-kilometre value: if the operating costs are calculated from private kilometres, a log of private driving must be kept. The chosen method must be applied consistently, and the monthly value then does not cap the benefit.
• Lower value: if private driving according to the log stays below 18,000 km a year, the employee can claim a reduced car benefit value on the pre-completed tax return.
• High work mileage: if work driving exceeds 30,000 km in a calendar year, the benefit’s base value is 80 % of normal. The limit is absolute, and the log must be checked at year-end.
• Higher value: if private driving exceeds 18,000 km in a calendar year or 1,500 km per month of benefit use, the taxable value must be increased.
• Several users: if several employees use the same car, splitting the benefit by kilometres always requires a log or other reliable evidence.

A car benefit log can be manual or electronic. It must show the kilometres driven each day, split between work and private driving. For work drives, also record the start and end time, start and end point (route where needed), odometer readings and trip length, the purpose and the driver. For private drives the kilometres are enough. The employee keeps the log and gives it to the Tax Administration only on request.

Limited companies and partnerships

The additional deduction is available only to sole traders, self-employed professionals and farmers, and to a spouse who runs the business together with them. It does not apply to activity taxed under the Income Tax Act (TVL), such as freelancers or employees, nor to shareholders of a limited company (osakeyhtiö) or partners in a general or limited partnership (ay, ky). A company owner typically faces two situations:

• The owner drives for the company in their own car. The company can pay a tax-free kilometre allowance even if the owner draws no salary, as long as the conditions of the Tax Administration’s decision are met and a travel expense claim is made for the company’s books.
• The owner uses the company’s car for private driving too, including home–work trips. That is a car benefit. It is valued under the fringe benefit decision if it is treated as salary in the books and reported to the Incomes Register; unusual or unjustified benefits can be taxed as a hidden dividend.

For a company car, the log is the material with which the owner shows how much private driving there really is if they want the per-kilometre value or claim a lower value.

Is an electronic log or GPS app acceptable?

Yes, if it shows the same details as a paper log. According to the Tax Administration’s fringe benefit guidance, a log can be manual or electronic, and an employer can fit a benefit car with a GPS-based tracking service that replaces the log. Travel expense claims can be made in an app as well. For a sole trader’s additional deduction the law does not prescribe a format; it requires a driver’s log or other reliable evidence.

When choosing an app, check three things:

• GPS records times, places and kilometres, but not the purpose of a drive. The purpose and the driver must be added to every business drive.
• The whole year’s kilometres must be visible, private driving included – business drives alone are not enough.
• The data must be printable or exportable to a file. Under the Accounting Act, accounting material must be viewable and, where needed, printable in plain form, and its content may not be changed after the financial statements are prepared. Export the year’s drives at the latest when closing the year, so the data does not disappear if you switch apps.

For the firm’s clients, an electronic driver’s log can also be enabled in the Vaavo app.

What if no log was kept?

A missing log does not by itself remove the deduction, but the trader must then prove the drives in another way. According to the Tax Administration’s guidance:

• An additional deduction without a log is possible only if the business kilometres can otherwise be established reliably. For regularly repeated trips, such as once a week to the same place, state the trip length and how many times a year it is made.
• The car’s total kilometres for the year must always be established. Without them it cannot be verified that the car belongs to private use, and no additional deduction is granted.
• In that case the actual costs of business drives are deducted first, for example from fuel receipts. If even those cannot be established, the deduction is calculated at the per-kilometre rate for home–work trips (€0.27/km for a car for tax year 2025), which is clearly lower than the kilometre allowance. The condition is that costs were actually incurred.
• If private drives in a business car cannot be shown reliably, their share is estimated.
• If there is no reliable evidence of business drives at all, no private car costs are deducted from business income.

For a car benefit, the monthly value applies unless private driving is shown with a log or other reliable evidence, such as the car’s total kilometres. Inadequate evidence can also lead to a tax increase (veronkorotus). Under the Act on Assessment Procedure it is generally 2 % of the added income, but at least 3 % and at most 10 % if the failure is repeated or shows obvious disregard for tax obligations. For a natural person the tax increase is at least €75. It is not imposed if the failure is minor or there is a valid reason for it.

How long must the log be kept?

• Sole trader: a natural person carrying on a business or profession is obliged to keep accounts. Under the Accounting Act, vouchers and other accounting material are kept for at least six years from the end of the year in which the financial year ended, and the books and financial statements for at least 10 years from the end of the financial year. The log supports the car costs and the additional deduction, so keep it with the accounting material for at least as long as the vouchers.
• Employee: receipts and documents for the tax return are kept for 3 years after the end of the tax year, and longer in some exceptional cases. The Tax Administration says a driver’s log, if you have one, must be kept even though documents on home–work travel otherwise need not be. Records may also be kept electronically.
• Employer: travel expense claims and their attachments are the vouchers for booking the reimbursements, so the Accounting Act retention periods apply to them.

Work car registered abroad

A separate log obligation exists in car taxation. Under section 39 of the Car Tax Act, a person permanently resident in Finland whose employer has a fixed place of business abroad may use in Finland, tax-free, a vehicle permanently registered abroad and owned or held by the employer. The same applies to a self-employed professional resident in Finland who has established themselves abroad or provides services abroad, for their own vehicle registered abroad. In addition, the vehicle must be used on fewer days in Finland than abroad in each 12-month period; if it is used in both Finland and abroad on the same day, the day counts as use abroad. For such use, the user and their family members must keep a paper or electronic log. It records, per day or per drive, the day of use or the start and end time, the kilometres or odometer readings, the country of use and the driver, plus the total days of use in Finland and abroad over the 12-month period. It must be kept so that the original data can be verified and shown to the Tax Administration on request. What matters is the employer’s fixed place of business abroad, not the number plate: a car registered in Estonia, for example, cannot be used tax-free in Finland under this rule if it is owned or held by a Finnish company without a fixed place of business abroad. Check the conditions before you start using the car in Finland.

Common mistakes

• Starting the log only when the Tax Administration asks for evidence. A list put together afterwards usually lacks times and odometer readings, and its reliability is hard to show.
• No total kilometres for the year. Business drives alone are not enough: without the total, no additional deduction is granted.
• Monthly totals and vague destinations such as “Turku” or “customer visits”, with no start and end times. Such a log does not show how long work trips lasted, so a per-diem-based additional deduction cannot be granted. In the Tax Administration’s example, the claim for 150 days was refused and a tax increase was imposed.
• Logging the drive from home to your own premises as business driving. It is private.
• Claiming the additional deduction for a car owned by parents, a relative or a leasing company. Only actual costs can be deducted for it.
• Deducting the same car costs twice: in the books and as a full additional deduction. Costs deducted in the books reduce the additional deduction.
• Raw GPS data without the purpose of the drive and the driver.
• A limited company owner claiming the additional deduction. Their trips are reimbursed through a travel expense claim, and private use of the company car is a car benefit.

Help with car costs and the driver’s log

We handle bookkeeping, payroll and tax returns for sole traders and limited companies. We check whether a car belongs to the business or to private use, calculate the additional deduction or the private-use share from the log, and handle car benefits and travel expense claims in payroll. We work in Finnish and Russian – get in touch and we will go through your company’s car matters.

Official sources

• Tax Administration: vehicle expenses of the self-employed and the driver’s log
• Tax Administration: detailed guidance on deducting a trader’s travel expenses (in Finnish)
• Tax Administration: tax return instructions for traders (in Finnish)
• Tax Administration: fringe benefits from employment and the car benefit
• Tax Administration: detailed guidance on fringe benefits (in Finnish)
• Tax Administration: detailed guidance on travel reimbursements and the travel claim (in Finnish)
• Tax Administration: receipts and other documents – how long to keep them
• Tax Administration: decision on the driver’s log for car tax purposes (in Finnish)
• Finlex: Business Income Tax Act (360/1968), section 55 (in Finnish)
• Finlex: Accounting Act (1336/1997), chapter 2 section 10 (in Finnish)
• Finlex: Act on Assessment Procedure (1558/1995) (in Finnish)