in arrears
Behind or overdue, often because one has not made a payment as scheduled. Their account is in arrears, so I doubt we'll see money from them any time soon.
*in arrears
[of debts; of an account] overdue. (*Typically: be ~; get ~.) Jane's student-loan payments are in arrears. The accounts of the bankrupt company were in arrears.
in arrears
Late or behind, especially in payment of money. For example, He's been in arrears on his rent so often that he may be evicted. [First half of 1600s]