What term refers to unpaid or overdue debts?

The term that refers to unpaid or overdue debts is "arrears." When a borrower or debtor fails to make the required payments on a debt, those payments become overdue, and the total of these overdue payments is referred to as being in arrears. This term is often used in contexts like overdue mortgage payments, rent, or other types of loans where payment schedules are established but not adhered to.

Although "liabilities" also relates to debts in a broader sense—encompassing all types of financial obligations a person or entity owes— the specific notion of overdue payments aligns more closely with the term "arrears." Meanwhile, "assets" refer to what a person or entity owns, and "equities" pertain to ownership interests in assets, particularly in relation to stock ownership. Thus, "arrears" is the most precise term when specifically indicating debts that are unpaid or past due.