The quantitative conversion of fluorosulfates into trifluoromethyl sulfates is systematically investigated. The reaction proceeds initially according to the general equation[Formula: see text]where E is a coordinatively saturated metal or an organometallic moiety. However, the key to a quantitative substitution is the observed degradation of the SO3F group by excess HSO3CF3 and the noted observation of various volatile by-products that do not appear to interfere in the isolation of analytically pure trifluoromethyl sulfates. The fluorosulfates selected are representatives of the most common bond and coordination types—ionic or covalent with coordination through one, two, or three oxygens of the SO3F groups. The selected substrates display a fairly wide range of solubilities in HSO3F. All conversion attempts are successful except for one, that of polymeric Hg(SO3F)2, and a number of new SO3CF3 derivatives of tin, platinum, germanium, and palladium are described. The solvolysis of tin(IV) acetate in HSO3CF3 is reinvestigated and the syntheses of two other trifluoromethyl sulfuric acid derivatives, CsSO3CF3•HSO3CF3 and CH3CO2H•HSO3CF3, are described.