An unconditional written promise to pay a specified amount at a fixed future time is known as what?

A promissory note represents an unconditional written promise made by one party to pay a specified sum of money to another party at a defined future date or on demand. This legal document details the principal amount, interest rate (if applicable), repayment schedule, and any other relevant terms associated with the loan.

In the context of financial instruments, a promissory note is distinct because it is straightforward in its obligation—one party owes a specific amount to another without any conditions that would alter the promise. This simplicity makes promissory notes a common tool in various financial transactions, especially when individual loans are made.

In contrast, a bill of exchange involves an order from one party to another to pay a third party and is often used in commercial transactions. A loan agreement typically encompasses more terms and conditions than just the promise to pay a specific amount, focusing instead on the overall contract terms between the lender and borrower. Lastly, a debenture is a type of debt instrument that companies utilize to secure funds from the public, usually backed by the general creditworthiness of the issuer rather than specific assets. Thus, the defining characteristics of a promissory note align perfectly with the description in the question.