The Schultz name is spelled lots of ways ... even by closely related Schultzes. My great grandfather spelled his name without the c ... Shultz ... but no one else in the family does. Our family name was originally Scholze, with an umlaut on the o, but it was anglicized to Schultz after the family emigrated to America in 1734. Scholze would still be pronounced the same. It German, the name Schulz would still be pronounced as if there were a T before the Z.
