Salt Lake County Mayor. Download it for free now.An incentive bonus agreement is a contract between an employer and employee that details information about a cash bonus offered as an incentive. Want to know how to make your employees feel valued? Select a bonus letter example that truly speaks to them with our template and guide. Customize and Download this "Bonus Request Letter". What is a Bonus Plan? A bonus plan is an agreement between the employer and employee to pay out a predetermined amount of money based on performance.