Learn how to write a letter for declining a job offer that you have already accepted and use our template and example as a guide. When writing a job offer rejection letter, you must be clear about your purpose and honest to tell them your reason for declining.A followup thank you email after a job rejection letter is so rare, you will stand out and it may lead to future recommendations or another job. I'm sorry to say that your candidacy did not make it to the next round; we've had a very competitive pool for this position. Just write them a letter thanking them for the opportunity but you decided to pursue other options at this time. We recommend you combine your cover letter and resume into a single document before you start the job application process for the City of Phoenix. Giving a timely response is the most polite. The quicker you respond, the quicker the employer can fill the role. 1. Let your employer know as soon as possible. Avoid letting your employer wait too long.