A tax addition is calculated based on the list value, also known as the value for tax purposes. This is the value of the vehicle when it was first delivered, the new price. This can almost always be found in the lease agreement. For example, if the value is €30,000, at a 22% tax addition rate that comes to €6,600 per year. The tax authorities designate this as additional gross income. The list value is adjusted to the current value by most rental companies. Whether a tax addition is actually applied and how high it will be depends on a number of factors.
The main factor that determines whether there will be additional charges is the number of kilometers driven. If you drive more than 500 kilometers privately on an annual basis with a business rental car, you must pay a tax addition. Private kilometers driven are those that are for trips that are not commuting or work-related. This obviously includes the drive from home to work, but also, for example, customer visits, deliveries and on-call shifts.