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. Learn the essential steps on how to add a cosigner to a lease to strengthen your rental agreement.A cosigner for an apartment takes on the financial responsibility for a lease. Learn how having a cosigner can help someone get approved for an apartment. Adding a cosigner is pretty straightforward with these steps: Do your research: Treat the apartment cosigner as an additional tenant. This guide will provide all the necessary information you need to screen, process, and add a cosigner to a lease. They are now asking for my husband, her stepfather, to also sign the lease. Is this the law in Pennsylvania that both a husband and a wife must cosign a lease? In a nutshell, you must pay a full month rental deposit, fill out an application form and pay an application fee online for each tenant and each cosigner. Find information about rental code violations, how to file a complaint, and other tenant resources.