Used primarily as an intermediate in organic synthesis, particularly in the preparation of sulfonate esters and sulfonamides. It serves as a chlorosulfonylating agent, introducing the chlorosulfonyl group into various substrates. This compound is valuable in pharmaceutical manufacturing for modifying molecular structures to enhance reactivity or stability. It also finds use in the development of agrochemicals and specialty polymers due to its ability to form covalent linkages with alcohols and amines. Handling requires caution due to its reactivity with moisture and potential to release corrosive fumes.