My dad has agreed to cosign a lease with me but I am afraid my application will just be thrown out since I cannot provide a credit score or any proof of income. To cosign, the person must have a clean rental history and not have gone through any evictions.Applicant is an additional person you add to the rental application and resulting lease agreement for an apartment. Below, we will guide you through what a lease cosigner is, the pros and cons of adding a cosigner, and how to add a cosigner to a lease. You can ask a family member or someone you trust to act as cosigner. CHECK AND COMPLETE ONE of the two following sections that applies to you, the undersigned. The Housing Authority of the County of Contra Costa accepts pre-applications online when we anticipate housing becoming available within a few months. When I apply online, who has to fill out an application? Everyone over the age of 18 must submit an application on time.