Debtor

What Does Debtor Mean?
A company or individual who owes money. If the debt is in the form of a loan from a financial institution, the debtor is referred to as a borrower. If the debt is in the form of securities, such as bonds, the debtor is referred to as an issuer.

Investopedia explains Debtor
It is not a crime to fail to pay a debt. Except in certain bankruptcy situations, debtors can choose to pay debts in any priority they choose. But if you've failed to pay a debt, you have broken a contract or agreement between you and a creditor. Generally, most oral and written agreements for the repayment of consumer debt - debts for personal, family or household purposes secured primarily by a person's residence - are enforceable.
 
However, most debts for business or commercial purposes must be in writing to be enforceable. If the agreement requires the debtor to pay a certain amount of money, then the creditor does not have to accept a lesser amount.  Also, if there was no actual agreement but the creditor has loaned money, performed services or provided the debtor with a product, that debtor must pay the creditor.