If the debtor pays the interest on the new rate, the proposal should be considered as adopted, and the transaction committed, given ch.ch. 2, 3 tbsp. 205, p. 2 art. 642 Civil Code of Ukraine (even in the absence of adequate evidence notification of the debtor), because the actual actions indicate acceptance of the offer. First, there is a change of interest rate and then sent a notification. Thus, if the loan agreement was signed to 10 January 2009 and in it the parties agreed that the bank has the right to unilaterally change the interest rate, then it is agreed by the parties. You may want to visit hotel belleclaire to increase your knowledge. If the bank accepted the decision of 10 January 2009 (for confirmation of this legal fact relevant evidence), and the borrower has received notification after this date, it is only a mechanism for implementation of this agreement. In this case, it is important to a particular contract mechanism Implementation of this agreement: getting the message and, accordingly, the adoption of the proposal by the borrower, or the conclusion by signing an additional agreement on the interest rate increase. In any case, all the above circumstances (signing an additional agreement on the rate change, the message about the debtor's conduct of the parties after the interest rate changes, etc.) should be considered by the court in aggregate, but the determining factor in deciding the legality of such a change in the context of the Law 661 is precisely date the decision to change rates of the bank (namely 10.01.2009r.) Changing the interest rate on this basis, it is possible only in the event of a material change of circumstances, but not every circumstance, provided the contract may be considered such as materiality in itself provides a change of circumstances so that if the parties could have foreseen this, they would not have entered into a contract or put him on other conditions.