Chicago law requires landlords to allow tenants to sublease their apartments if requested. Here's what else you need to know about subleasing in Chicago.You can, but it's not a good idea. Most leases prohibit subletting, or only allow it with permission. Illinois tenants are generally allowed to sublet, unless their lease specifically prohibits it. Tenants generally can't sublet their unit without the landlord's consent. Protect your rentals with Avail lease agreements and amendments. If the lease allows subletting only with the landlord's permission, it is likely enforceable. There's no fine for that. Landlord can seek to terminate the lease if there is an unauthorized sublet, but that takes a long time in court.