The authors agree that the surname derives from a nickname, although they differ in the base term. E. Rossoni notes that the origin would be in the Venetan dialectal term finco (finch), which in the past also had the meaning of "astute" and "shrewd". Rossoni characterises it as clearly Venetan, especially spread in the Vicenza and Padua areas.

F. De Laurentiis proposes, on the other hand, that the base is the noun finca, with the sense of "column of a register or of a table", from which arose the nickname finco, applied above all to accountants and to those who kept records.