We are writing you this letter to notify you that [Date] marks your fifth anniversary with [name of firm]. Thank you very much for the five years of your devotion, hard work, dedication, and loyalty to our company.
We value you, as well as our other highly capable staff members, as our company’s growth and success could not be reached without you. We recognize your great contributions in achieving the position we are currently at in this industry.
We hope that you will be with us in the following years. Congratulations on this anniversary.