👉 The term "submortgage" refers to a mortgage loan that is secured by a property, but not yet fully paid off. The borrower who takes out this type of loan typically has an existing mortgage on their home or other property, and they need to pay back the amount owed on the submortgage in order to make payments on the main mortgage. Submortgages can be difficult to understand for borrowers because they often involve a higher interest rate than traditional mortgages. They are also subject to stricter