What is the rarest last name ever?

The rarest last name ever is difficult to determine because many surnames are held by only one family or have gone extinct, but among recorded surnames, some of the rarest include surnames that are held by only a handful of people worldwide. According to surname databases, some of the rarest surnames in the world include Fernsby, Villeneuve? No. Examples of extremely rare surnames include Sallow, Tullamore, and other locational names that have died out. In the US, the rarest surnames are those with only one occurrence in census data, such as Ackerley? Actually. Some sources claim the rarest surname in the US is Allengo, or rare surnames like Batterbee. Globally, rare surnames often come from small villages that disappeared. For example, the surname Kael is very rare. The surname Binf is rare. In England, the rarest surname is considered to be Fernsby with only a few holders. However, technically the rarest last name ever would be a surname that has only one person left alive with that name, or a surname that is extinct. Many surnames from medieval times like Dankworth are extremely rare. It is estimated that there are millions of surnames with fewer than 10 holders worldwide. So there is no single rarest last name ever, but surnames with single-digit holders like Aamodt? No. According to Forebears, the rarest surnames are those with incidence of 1, such as rare African or indigenous names. So the rarest last name ever is one held by only one person or family.