It's considered best practice to sign a written apartment lease for all Chicago tenants and landlords. But did you know that under Illinois law, residential leases need not be in writing unless the lease term is for more than a year? (See the Statute of Frauds, 740 ILCS 80/2). Even an oral rental agreement for a term longer than a year may still be enforceable, though only as a month-to-month tenancy. See Luster v. Estate of Cohon, 11 Ill. App.3d 608 (1st. Dist. 1973).

Let’s assume that the landlord and tenant have agreed to sign a rental lease agreement. Both parties will want that lease to be enforceable, and as such, they must both sign the agreement.

Do Roommates All Need to Sign the Same Chicago Apartment Lease?

What about roommates? Should they both sign the apartment lease? Yes, and it benefits both the tenants and the landlords if they do. Let’s suppose that Tenant A signs the lease, but Tenant A’s roommate, Tenant B, does not sign the lease. In that case, Tenant B’s occupancy would be a material breach of the lease, assuming that the lease states that the premises may be occupied only by Tenant A (along with their minor children). The unauthorized roommate’s occupancy would be a material breach of the lease and could be the basis for its termination by the Landlord. So, Roommates, make sure you are all on the lease so that you don’t get evicted!

Another good reason for all roommates to sign the lease is to protect the roommates and confirm that each roommate is bound by the lease and obligated to pay their share of the rent or costs of repair to a damaged apartment. Would you, as Tenant A, be happy if your roommate Tenant B skipped out and left you obligated for the entire rent (and no recourse against the roommate who “skips out”)?

And as for the landlord, the landlord will find it beneficial to have all the roommates named on the lease so that the entirety of the rent may be collected from any of them. This concept, called joint and several liability, means that when Tenants A and B each sign the lease as Tenants, they each take on the responsibility for paying the entirety of the rent to the landlord. So, even if Tenants A and B decide to a 60/40 split (maybe Tenant A got the larger bedroom or a better view), and Tenant B later moves out or falls into economic hardship, the landlord can go to either Tenant A or Tenant B to collect the entire rent. Some roommates find it helpful to negotiate a roommate agreement that requires each to pay their share of the rent (and perhaps to agree to other conditions, like rules and responsibilities regarding cleaning, shared food, parties, and noise) to cover themselves in this regard and define their duties and responsibilities to each other.

And what about guarantors? If a landlord is uncomfortable with a potential tenant’s credit score, employment history, or income, the landlord might ask the tenant to provide a guarantor. That guarantor promises guarantees the performance of all tenant obligations, monetary and otherwise, i.e., to pay the landlord the entirety of the rent and any other money due under the lease. The guarantee must be signed to enforce this promise against the Guarantor. Many form apartment leases contain a guaranty provision for this purpose. You will almost always see landlords who rent housing to students requiring a personal guaranty from each student’s parents. Why? Because the parents presumably have money, i.e., assets, to satisfy a judgment for unpaid rent where multiple student roommates' leases have multiple guarantors, those guarantors (parents) are wise to have an agreement between/among them so that one parent/guarantor has recourse against the other guarantors if the landlord gets a judgment against one or more guarantors.

LEGAL DISCLAIMER: The general information that Domu provides about Chicago landlord tenant law is not intended as legal advice. Domu endeavors to provide accurate information, but the law is subject to change, and Domu is not a law firm or provider of legal services. Questions about your particular leasing situation should be directed to a lawyer.