A method of computing the unearned premium reserve. It is assumed that, on average, policies run from the middle of the month of inception. The appropriate number of twenty-fourths of premiums relating to the policies commencing in each month is then carried forward as unearned.

A warranty used in catastrophe excess of loss reinsurance to ensure that the reinsurance is not invoked unless at least two distinct risks are involved. Involvement in single losses applies to working cover excess of loss treaty. The warranty is used in life, personal accident, catastrophe property and reinsurance in the London excess market (LMX).