Employment Offer Letter Instructions. A job offer letter isn't a contract.It doesn't require a signature and, as you've experienced, a signature doesn't guarantee a job. Include a space where the potential employee can sign and date the letter to signify their acceptance. It's perfectly okay to reply with, "Thank you for the offer. I really appreciate it. The short answer is yes, you can decline the offer. I suspect that the offer letter says that when you become employed, you would be an employee at will. Congratulations on the job offer! The offer letter is usually sent out after either HR or the hiring manager calls the candidate to verbally offer them the job.