There is no specific ceiling for interest rates, however, the interest rate can't be disproportionate, otherwise it can be defined as usury.Usury is defined in the Criminal Law: For a person who commits the making of loans in whatever form, knowingly taking advantage of the grave economic situation of the borrower of the loan, and the terms and conditions of which are excessively burdensome for the borrower (usury),the applicable punishment is temporary deprivation of liberty or community service, or a fine.