The premiums for Workers' Compensation and General Liability are based on estimates at the start of the policy. After the policy expires, the insurer will adjust the premium to reflect the actual exposures the insured had during the policy period. This process is called

A policy endorsement is a modification or addition to an insurance policy that changes the terms, coverage, or limits. While endorsements can adjust coverage mid-term, they do not pertain to the process of adjusting premiums based on actual risk exposure after the policy period.

An installment refers to a payment method where the total premium is divided into smaller payments. This term does not relate to the assessment or adjustment of premiums based on actual exposures after the policy has expired, which is the focus of the question.

Experience rating is a method used to adjust premiums based on the insured's past claims history and risk profile. Although related to premium adjustments, it does not specifically refer to the post-policy review of actual exposures, which is what an audit entails.