In reinsurance, this term is applied to the nouns: insurer, insured, policy and insurance and means respectively: 1) the insurance company that initially originates the business, i.e., the ceding company; 2) the policyholder insured by the primary insurer; 3) the initial policy issued by the primary insurer to the primary insured; 4) the insurance covered under the primary policy issued by the primary insurer to the primary insured (sometimes called “underlying insurance”).
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Basic, fundamental; an insurance policy that pays first with respect to other outstanding policies.