The authors agree that the surname presents several hypotheses of origin. The most probable, according to both, is that it derives by apocope from the place name Borgoratto, in the Alessandria area. They also agree in noting a possible derivation from the Germanic term rat, "counsel," referring to a bearer of the surname who would have been an important representative of his community.

E. Rossoni adds that the use of this name or nickname is documented in a deed of 1338. F. Miranda, for his part, incorporates a third hypothesis: that the surname derives from a nickname linked to the agility and speed of the first bearer, by association with the animal (ratto, "rat" in Italian).

As to the geographic distribution, Rossoni notes it as typical of the Ligurian and Piedmontese area, with a presence in the Alessandria, Savona and Genoa areas, and secondary areas in Rome, Naples and Sicily. Miranda specifies that the main nucleus is concentrated in Piedmont —especially in the Alessandria area— and in Liguria, with a smaller presence in Lombardy, Sicily, Campania, Lazio, Veneto, Emilia-Romagna and Tuscany. In Sicily, he details specific nuclei in the Messina, Catania, Palermo, Enna, Agrigento and Caltanissetta areas.