Last updated: 12/01/2026‍

In Belgium, the mileage allowance is an important form of compensation for employees who use their private car for professional travel. A correct and tax-free reimbursement can have a significant impact on employees’ net income. In this article, we cover everything you need to know about the mileage allowance in 2026, how it is calculated, whether a reimbursement is mandatory, and what the maximum tax-free mileage allowance is.

This mileage allowance should not be confused with the commuting allowance for travel between home and work using a private car. In this case, it applies exclusively to professional travel carried out in the context of performing one’s job.

What is the mileage allowance for professional travel in 2026?

The mileage allowance for commuting is an amount that an employer may grant tax-free to employees who use their private car for work-related travel (e.g. visiting a client). Since 2022, in addition to the annually indexed mileage allowance (Royal Decree of 18 January 1965), there has also been a quarterly indexed mileage allowance (Royal Decree of 13 July 2017).

This amount is adjusted every quarter to better reflect fluctuations in fuel prices and other transport costs. Which of the two allowances must be applied depends on the sector in which the company operates. If nothing is specified in the Joint Committee, the employer may choose which allowance to apply for the entire validity period of that allowance.

For the first quarter of 2026, the maximum tax-free mileage allowance is set at €0.4326 per kilometre. For the annually indexed mileage allowance, the amount is set at €0.4449 per kilometre for the period from 1 July 2025 to 30 June 2026. These maximum amounts also apply to company directors who make professional trips for their own company.

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Table: Maximum tax-free mileage allowance for professional travel per quarter

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Employers may choose to pay a higher allowance to their employees, but amounts exceeding the above limits are considered taxable income, unless they correspond to the actual cost (the burden of proof lies with the employer).

How do I calculate the mileage allowance for professional travel?

The calculation of the mileage allowance is relatively straightforward and can be done using the following formula:

Formula: number of kilometres travelled × mileage allowance

Example calculation:

Suppose an employee travels 40 kilometres per day for professional purposes. With 20 working days per month, this amounts to a total of 800 kilometres per month. The company sector stipulates that the quarterly indexed mileage allowance must be applied.

Calculation:

800 km × €0.4326 = €346.08 tax-free reimbursement per month.

This allowance is usually paid out monthly and helps employees offset part of their travel expenses. The total amount paid by the employer must also be reported on the tax form.

Why is the maximum mileage allowance now also adjusted quarterly?

Since 2022, the maximum tax-free mileage allowance in Belgium has been adjusted every quarter to better respond to changes in fuel costs and general transport expenses. By adjusting the allowance quarterly, the government aims to ensure that the mileage allowance remains realistic and fair for both employers and employees.

The allowance is determined by the Federal Public Service Finance and may vary from quarter to quarter. Employers can reimburse employees tax-free for work-related travel up to the maximum amount set for each quarter. This amount may increase or decrease depending on economic conditions.

An amount of up to 24,000 kilometres per year per employee is considered tax-free by the tax authorities. The National Social Security Office (RSZ/ONSS) has not set a maximum limit.

Is a mileage allowance for professional travel mandatory?

As an employer, you are required to reimburse employees for expenses incurred for professional travel. This flat-rate mileage allowance for professional purposes is one possible way to do so, but it is not legally mandatory in Belgium. The conditions and amounts may vary per company and sector and are often laid down in the employment contract or in a company policy.

What is the maximum mileage allowance in Belgium?

The quarterly indexed mileage allowance is capped at €0.4326 per kilometre for the period from 1 January 2026 to 31 March 2026. The tax-free annually indexed mileage allowance is capped at €0.4449 per kilometre for the period from 1 July 2025 to 30 June 2026. This means that an employer can grant this allowance without either the employer or the employee having to pay taxes on it.

If an employer pays more per kilometre, the amount exceeding the limit is taxed as salary. For this reason, most companies adhere to the maximum tax-free amount per kilometre in order to avoid additional costs.

What is the flat-rate mileage allowance?

The flat-rate mileage allowance is a fixed tax-free reimbursement granted by employers to employees who use their private car for work-related travel. This flat-rate allowance is intended to cover actual costs without requiring employees to submit receipts for every kilometre.

The flat-rate allowance applies only to work-related travel. Employees who regularly make professional trips may benefit from a flat-rate allowance to reduce administrative burdens.

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