Mortgage loans, can hire to fixed interest, Variable interest, or mixed. In this paper we will make appointments at the rate of interest fixed which is a type of permanent interest that applies to the stipulated capital and for a certain period of time that appears in public deed gives as a result the letter that we will pay over the life of the credit. This fixed interest rate does not give us scares by the models of interest increases, this is the advantage of the fixed interest when signing the mortgage loans. The characteristic of fixed interest rates is not more than your evidence in fixed the amount that we will pay for the time and duration of the fixed quota mortgage has its pros and cons the serious option when the Euribor rises in your interest mortgage loans fixed to be signed to a fixed model this does not change but the disadvantage is that if the Euribor in your mortgage to fixed rate decreases your amount not It decreases by what deposit more than the average. A fixed rate mortgage is usually granted to a time of hiring or certain period of 15 years, this causes a rise in the amount variable interest rates are normally contracted to a maximum of 35 to 40 years of which much less is the payment of a fee. Although if the orientation of the market is down and you have purchased a mortgage loan to model fixed always may require a review of your mortgage obligations to improve them to your bank. In the event your bank not the best support them alternative is a subrogation mortgage between banks its cost is infimo and their positive objectives depending on the model of interest.