The court said that companies were able to ban “the visible wearing of any political, philosophical or religious sign”.
The ruling made clear that if the ban was only applied to Muslim members of staff it could still constitute “direct discrimination”.
The case was brought by two women – one living in France and one in Belgium – who were dismissed from work after refusing to remove their headscarves.
Companies would need to already have a policy in place prohibiting the wearing of religious symbols and would not be able to ban staff from wearing headscarves on the “wishes of a customer”.
The court statement read: “An internal rule of an undertaking which prohibits the visible wearing of any political, philosophical or religious sign does not constitute direct discrimination”.
“However, in the absence of such a rule, the willingness of an employer to take account of the wishes of a customer no longer to have the employer’s services provided by a worker wearing an Islamic headscarf cannot be considered an occupational requirement that could rule out discrimination.”