Generally a job offer letter will show your new salary and that will help that you will be financially able to pay rent. Applicants for Staff and Administrator positions are required to submit a letter of interest.Step 5 is where you fill out the full application for the Voucher Choice Program. Click on the job title, and then Apply, to complete the application. Learn the key elements of a successful apartment offer letter, including job details, rental history, and ways to stand out to landlords. Cover letters and résumés are two of the most important documents you need to successfully complete your job search. The apartment I'm applying for wants me to share my offer letter for proof of income. On the letter it says confidential.