In this report, we describe an LMCT-based iron-catalyzed strategy for the decarboxylative fluorosulfonylation of aliphatic carboxylic acids, using DABSO as the SO₂ source and NFSI as the fluorine reagent. The Fe(III)/Fe(II) redox cycle enables simultaneous activation of the carboxylic acid and reduction of the sulfonyl radical. This strategy efficiently generates sulfonyl fluorides under mild conditions and facilitates late-stage functionalization of drugs, natural products, and peptides.