By 2016, interest rates set by the European Central Bank reached historic lows. For this reason, a mortgage loan has become a more common way of financing the purchase of real estate. However, it is to be expected that, at some point, the current interest rates will be subject to alteration. Consequently, mortgage loan agreements usually contain a provision authorizing the bank to unilaterally increase the respective interest rate. Hence, it is particularly significant that one of the most frequently used banking products on the Slovak market is the mortgage with variable interest rates, with their possible fixation during the subsequent 3-5 year period.