Blended rate mortgages are a combination of a fixed rate mortgage and an adjustable rate mortgage. This means that for example in the first few years the monthly amount does not vary and remains at a fixed rate, as in fixed rate mortgages. As soon as the agreed fixed rate period expires, the mortgage holder starts paying the variable rate. The monthly payments will vary and will increase or decrease depending on their reference index, in most cases the Euribor. This fluctuation depends on the terms set for the interest rate review, which is usually every 6 to 12 months. This type of mortgage is very similar to adjustable rate mortgages, including some special terms and conditions.