If an employee exercises his employment abroad, most double tax treaties allocate the right to tax the income related thereto to the work state if the employee’s presence in the work state exceeds 183 days per year. According to the Dutch court of appeal (Den Bosch), however, the days spent in the work state for personal reasons should be excluded for this test if the employee is a frontier worker travelling to and from work every day not having a pied-à-terre or apartment in the work state at his disposal. Should the state of residence not follow this interpretation, it could potentially lead to double taxation or double non-taxation.