A polite, but factual letter stating the reasons why you are declining the offer. If the salary offer is too low, say so.The letter should thank the candidate for their interest. It should explain why they were not selected for the position. Going beyond my job description and being the top in indirect roles does nothing. After much consideration and reflection, I have decided that I must decline the offer. Thank you for the offer that you extended for a position as a research assistant in the Department of Interior Extension Library. Received a letter from candidate's lawyer. Does he have any ground for compensation? If the employer gives you a deadline that seems reasonable to you, then try to accommodate the request.