A surety is a person who is approved by the court as your supervisor while on bail. The surety is someone who knows you well, usually a family member or close friend. A surety formally promises to the court to be familiar with your conditions, to discuss them with you, and to make sure that you are following them. A surety has to be prepared to take the difficult step of notifying the court or the police if you fail to live up to your promises. A surety also stands to lose the sum of money pledged if s/he does not supervise properly, a process known as estreatment. That sum of money pledged can be as low as $500 or as high as several hundreds of thousands of dollars for the most serious cases. Often, a surety has to pledge the equity in their home to guarantee bail, which illustrates how serious this commitment is.