According to <a href="https:&#x2F;&#x2F;www.ch.ch&#x2F;en&#x2F;married-name&#x2F;" rel="nofollow">https:&#x2F;&#x2F;www.ch.ch&#x2F;en&#x2F;married-name&#x2F;</a><p>&gt; 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.<p>So, it&#x27;s not &quot;official&quot; but you can use it everywhere including on your official documents.