The Munich couple, whose first names were not released, challenged the law after they married. They argued they wanted to share a surname, while each maintaining professional names — Thalheim is a dentist and Kunz-Hallstein a lawyer.

They said the law violated their right to free choice and could be damaging their careers.

But the Karlsruhe-based Federal Constitutional Court rejected their claim, ruling the law exists to prevent clunky "name chains," while still allowing couples to decide for themselves which last name, or two-name combination, they wish to take on.

"This addresses the wish to create names that are viable in legal and business dealings, while at the same time do not lead to name chains in later generations," the court wrote.

Germany has strict laws governing not only which surnames can be used, but also which first names can be given to a child.