Surety Law and Legal Definition

A surety is a person obligated by a contract under which one person agrees to pay a debt or perform a duty if the other person who is bound to pay the debt or perform the duty fails to do so. Usually, the party receiving the surety's performance will first try to collect or obtain performance from the debtor before trying to collect from the surety. A surety is often found, for example, when someone is required to post a bond to secure a promise.

Contracts sometimes contain a waiver of suretyship defenses. Defenses that may apply include modification of the obligation, release of security or of another party, impairment of recourse, and waiver and release by assignment, sublease, or bankruptcy. For example, such a waiver has the effect of waiving the defense of impairment of collateral. The definition of impairment of collateral includes failure to comply with applicable law in disposing of the collateral.