Calculate the amount of the debt. The principal amount is confirmed by primary accounting documents: invoice, acts of acceptance, acts of reconciliation of mutual settlements. Debt is calculated after the deadline for performance of an obligation.
Define the period of delay in payment. One of the most contentious issues that arise in court. As a rule, the obligor proves that the delay arose as a result of guilty actions of the creditor, disputing the start date of the late payments. Therefore, before filing a suit, the date of occurrence of delay it is possible to get a written confirmation of a debtor.
Make the calculation of penalties per day of delay. For this amount, debt rate, multiply by penalties. As a rule, fines for delay shall be recovered in the amount of the refinancing rate. The rate is set by instructions of the Central Bank of Russia. When calculating on the basis of the annual refinancing rate, in the numerator indicate the discount rate, the denominator is 360. For example, 28.02.2011, the rate on the day 8/360.
Finally, the interest amount equal to: the amount one day of delay multiplied by the number of days.