As a lawyer, I know all about unpaid bills. Doctors get their payments primarily from the Medical Services Plan (whatever its name in your province), which pays promptly and reliably, and secondarily from other institutions such as Workers' Compensation Boards, which also pay reliably although not always promptly. The result is that doctors seldom have any significant amount of overdue accounts receivable. Dentists face a much tougher time than doctors when it comes to collections.