All payments shall first be applied to outstanding late fees, then to interest and the balance to the Principal amount. In Poseidon, the parties executed a promissory note that provided for interestonly monthly payments, and a final balloon payment.A person who signs a promissory note along with the borrower. (c) Balloon Payment; Balance. All amounts not previously paid pursuant to this Note are due and payable on the Maturity Date, as it may be accelerated. 6.2.