Return to the Mortgage Glossary Home to view explanations for all mortgage terms. What follows is the definition for the term Additional Security Fee as it relates to mortgages in the UK. Additional Security Fee This is sometimes required when the mortgage exceeds a certain percentage of the value of the property (usually 75%). It takes the form of an up-front, one off fee paid to the lender to protect them against the borrower defaulting on the loan. Occasionally the lender may require a parent to be a guarantor or for other securities (such as other property or shares) to be made. This form of additional security is normally an Indemnity Guarantee Premium or Mortgage Indemnity Premium.     Previous 10 terms < Added To Loan < Accident, Sickness and Unemployment Insurance (ASU) < Valuation Fee < Valuation < SVR (Standard Variable Rate) < Survey < Self-employed < Self Certification < Repayment Mortgages < Redemption Penalty Next 10 terms Administration Fee  > Advance  > Adverse Credit  > Agreement in Principle  > APR - Annual Percentage Rate  > Arrears  > Bankrupt  > Base Rate  > Booking Fee and Arrangement Fee  > Building Society  >