This paper analyzes the patterns of early repayment in multi-period credit transactions. Considered one of the most common ways of conversion of unpaid interest for early repayment, so-called 78 rule. The relationship of this rule with the linear approximation of the exact value; redeemable debt is determined. The analysis of the maximum excess payment of interest on 78 rule. It has been shown how interest payment on 78 rule depended on the time of early repayment.

Early repayment of debt is an agreement under which the borrower pays to the lender amount of money equal to the current balance (as of loan account). Then further regular payments cease and the contract terminates. However, the amount of outstanding debt is determined by the structure of prescription charges. So in the uniform schemes of repayment of consumer credit each payment contains the same part of principal amounts and the total interest. In case of early repayment the Bank loses a significant fraction of the expected interest payments. Therefore, in practice, often used so-called accelerated schemes of interest payments. One of them is 78 rule. Use the 78 rule is simple and straightforward. The name of the rule is due to the fact that the sum of the numbers 12 monthly payments is 78. In the schemes of consumer loan with a term of one year interest payment for the current month is equal to m/78 of the total amount of interest payments, where m is the number of remaining payments. The rule name is stored and in the more general case with an arbitrary number of payments. In general interest payment is determined by the relative weight of the total amount of interest in each payment. In uniform schemes it is constant. In accelerated with a particular speed decreases. Therefore, additional cash expenses by the 78 rule may be considered as additional penalties for early repayment of the debt. It this article is shown how this penalty depends on time before maturity. It is shown that the magnitude of these penalties in monetary terms reaches the maximum value when the loan is repaid early between half and two thirds of the total of the loan term.