The Supreme Court ruled that, as a matter of good employer practice, employers have a duty to inform employees of relevant tax changes.
Main rule
Besides, the main rule, the Supreme Court said, is that the employee himself is responsible for complying with his tax obligations. Nor does the employer have an advisory role in this regard.
Special circumstances
But there may be circumstances whereby the employer is still obliged to inform the employee of changes relevant to the employee's tax position. This is particularly the case when the information is also relevant to the employer's obligations under payroll tax, as the employer should obviously have knowledge of such information. In addition, the Supreme Court considers the possible negative consequences for the employee to be important.
The case concerns two pilots with Swiss nationality, employed by KLM. Until 2012, these employees are not taxable in the Netherlands. After the new tax treaty between the Netherlands and Switzerland came into force, the pilots are taxable in the Netherlands. Additional income tax assessments are imposed on the pilots for 2017 and 2018, for which they hold KLM liable. This claim is upheld.
Damage
It is not clear from the proceedings exactly what KLM has to compensate the pilots. To the extent that that is the tax due on the post-clearance assessments, that compensation will again qualify as wages for tax purposes, on which the employee is liable to pay tax in the Netherlands.