The bsest answer to this frequent question.
Jeff Walters via LinkedIn
UL is not needed to sell to utilities in the USA. I have been designing and selling to this market since 1985. UL is not written into any IOU (investor owned utility) specs. Conformance to ANSI C136 standards is required.
UL or ETL or CSA is needed to sell to retail, commercial or industrial market. Needed in the DOT market. Helpful in the municipal streetlight market
UL products are not required for insurance