In 1840 the Senate of Hamburg (city-state government) passed a law stating that "künftighin auch ein oder zwei Mitglieder der hiesigen israelitischen Gemeinde, wenn sie sonst dazu qualifiziert wären, Notare werden könnten" (in future also one or two members of the local Jewish community might become notaries, if they otherwise were duly qualified). This change of mind of the senate was brought about by the death of the Jewish notary Meyer Israel Bresselau, who had been installed during French annexation in 1811. Riesser applied for the vacant position. From 1840 to 1857 he practised as a notary in Hamburg.