What is the Euribor in mortgages?

The Euribor (acronym of Euro InterBank Offered Rate) is the most used index for calculating variable interest rate revisions in mortgages. It is an official reference interest rate that is calculated as the monthly simple arithmetic mean of the daily values at which the main European banks lend money to each other.

In variable interest mortgages, the interest rate at which the borrower must return the borrowed amount comprises a fixed percentage and a reference index, which is normally the Euribor. The interest rate is revised every six months or every year, and varies according to the performance of the index to which it is referenced, meaning that the monthly instalments that the borrower must pay may go up or down. Therefore, there is a very close and binding relationship between the Euribor and mortgages.

In the first business days of each month, the Official State Gazette publishes the Euribor data for the previous month. The mortgage will specify what date will be used to get the official value of the Euribor, which will be considered when revising the instalments, whether for the month prior to the revision date or another.