> Surnames combined with a hyphen, such as Meier-Müller, are still allowed. Combined surnames are not official registered names, but may be used in everyday situations and recorded in your passport and identity card.
So, it's not "official" but you can use it everywhere including on your official documents.
> Surnames combined with a hyphen, such as Meier-Müller, are still allowed. Combined surnames are not official registered names, but may be used in everyday situations and recorded in your passport and identity card.
So, it's not "official" but you can use it everywhere including on your official documents.