A balloon mortgage is a home loan with an initial period of low or no monthly payments and a large payment at the end. A balloon mortgage allows you to enjoy low monthly payments for several years — with a big catch.Writing a promissory note should be tailored to your specifications of that particular loan. Check out a free preview of a promissory note at 12Law. A part of the loan was sold off. There may be options such as Refinancing, Modification or Extension.