E. De Stefani links this surname with the given name Facio or Facino, abbreviated forms of Bonifacio. This name comes from the Latin Bonifatius, in which the expression bonum fatum, "good fate", is recognised, used as an augural name with the sense of "may he have a good destiny". Two saints bear this name: Boniface of Tarsus, martyr of the 4th century, and a second Boniface born in England in the year 675, who came to be bishop of the Germanic peoples in 722 and founder of numerous monasteries, which earned him the byname of apostle of the Germans.

E. Rossoni agrees that these surnames derive, directly or through augmentatives, from the aphaeresis of the name Bonifacio. According to Rossoni, Facci is typical of the Trento, Verona and Vicenza areas, with presence also in the Treviso and Padua areas. De Stefani, for his part, documents it in the northeast of Italy, in the regions of Veneto, Friuli-Venezia Giulia and Trentino-Alto Adige, with specific presence in the Carnia —a mountainous zone of the north of Friuli, in the province of Udine— from the beginning of the 16th century. The derived form Faccin, with a diminutive suffix, is recorded in that same area.