For general insurance, the required solvency margin is calculated on the basis of the premiums written and claims incurred by the firm. A risk factor is applied, to reflect the differing risk profiles of different classes of insurance. For long-term insurance, the required solvency margin is calculated on the basis of the aggregate of the mathematical reserves calculation and the capital sum at risk calculation. Refer to Chapter CA-2 for the detailed rules governing the calculation of the required solvency margin.