Even if your employer bases the calculation of the taxable benefit on the shortest route, you may still declare a longer route in your tax return if it is more convenient and you use it regularly.
For journeys between your home and primary workplace, you must pay tax on a surcharge in addition to the private usage value of 1 percent of the list price. This amounts to 0.03 percent of the list price per kilometre of distance for commuting each month.
In return, you may then, like any employee, claim the travel allowance of 0.30 Euro / 0.38 Euro per kilometre of distance as income-related expenses. If your employer taxes the taxable benefit for the company car at a flat rate of 15 percent, you must deduct the monthly flat-rate taxed amount from your income-related expenses and can only deduct the remainder as income-related expenses.
Even if the employer has only assumed 180 days for the calculation of the benefit value for simplification purposes, you can, for example, claim 220 days when deducting income-related expenses.
