Rationale for Award: Provide a brief explanation of why the bonus is being awarded. This fact sheet provides general information regarding bonuses and the regular rate of pay under the FLSA for non-exempt employees.There should be enough and valid reasons for writing the promotion letter. An incentive bonus agreement is a contract between an employer and employee that details information about a cash bonus offered as an incentive. The Frequently Asked Questions (FAQs) provided below highlight topics and specific questions that are often asked of the Illinois Department of Labor (IDOL). To inform employees about their bonus, you can send a bonus letter. Why Do Companies Offer Bonuses to Employees? A common example of an incentive is the signon bonus given when a new employee accepts an employment offer. The reason is simple. Qualified employee retirement plans.