[1] In 1854, Berendsen established his own firm which traded in iron, steel and glass, initially as a commodity broker but later as an import business.
[2] The firm prospered from the building boom that followed in the many new districts that emerged when Copenhagen's fortifications were decommissioned a few years later.
Berendsen died on 18 June 1884 in Copenhagen and is buried at the Jewish North Cemetery.
The firm was continued by his widow and after her death just two years later by their son Albert Berendsen.
Another son, Ivar Berendsen, was a customs inspector and politician, co-founder of the Danish Social Liberal Party.