Herein, the investigation of inorganic reagents containing the pentafluorooxosulfate (OSF5) moiety is presented. First, the gram-scale preparation of the reactive yet stable pentafluorosulfur hypofluorite (FOSF5) as well as its spectroscopic data are reported. Then, the preparation and full characterization of the corresponding fluorosulfonyl pentafluorooxosulfate (FSO3SF5, FSPO) by the fluoro-pentafluorooxosulfanylation of SO2 are highlighted. This liquid reagent (b.p. 39.6 °C) was later successfully used for modulable release of [cat][OSF5] ion-pair. The selective, in-solution release of SOF4 and SOF4/SO2F2 species was also demonstrated. Finally, the SuFEx reactivity was investigated and showed interesting reservoir ability. Indeed, we report the one-pot synthesis of sulfonyl fluoride (-SO2F) and sulfurimidoyl fluoride (─N═S(O)F2) species.