Tennessee-City of Chattanooga-Street Obstruction and Excavation Bond ($25,000) A surety bond or surety is a promise by a surety or guarantor to pay one party (the obligee) a certain amount if a second party (the principal) fails to meet some obligation, such as fulfilling the terms of a contract. The surety bond protects the obligee against losses resulting from the principal's failure to meet the obligation. As the obligee, the City of Chattanooga requires such a bond for contractors doing specific work within the city.