Before you can do any kind of background check on an applicant, you must get a signed consent form. If you live in Cook County, a landlord generally can't deny you housing just because you have an arrest or conviction record.One key requirement is obtaining written consent from the tenant before conducting a background check. Unlock the secrets to a seamless Illinois rental application process with our expert guide for landlords and property managers. Without this authorization, you cannot legally access their credit report. Clarify private housing applications and lease requirements, and discover safety tips for finding legitimate rentals. This law means landlords don't have to run a background check. If they do, they must follow certain rules. What the landlord can do is to use either Cozy or MySmartMove. You may not alter the rental unit without your landlord's approval.