A sample letter offering a job contingent upon the results of a background check or other criteria. Need help drafting a job offer letter?What is their job title and proposed start date? You may also include information about their probationary period, if applicable, and the date this ends. Your employment will be probationary for 90 days upon which we will review your performance and compensation. Follow these step-by-step instructions to create job-offer letters that reduce legal risks. Links to sample letters are included. An employment agreement probationary period is the word that describes the beginning stage of a task where an employer checks if an employee is fit for a job. No. It's different from a formal "Contract" of employment. Those become legal and binding upon joint signatures.