According to price regulation (German Preisangabenverordnung, PAngV), credit institutions are obliged to specify the total annual cost in a percentage of the credit and to declare the annual percentage rate. If the interest rate is subject to changes or if other factors determining the price are likely to occur during the term, the interest has to be declared ‘initial annual percentage rate’. For its calculation, interest rate, interest period, rate of redemption, redemption-free time, payout ratio, as well as the redemption model are taken into account in a fixed formula.