Add this addition to the standard lease to legally transfer the terms of the lease to a non-convict co-signer. Trust of more than 2.3 million homeowners and property managers Whether you are a landlord or tenant, a co-signed contract is useful in rental situations when it comes to the tenant`s financial situation. With the contract co-signed by a financially secure third party, the tenant and landlord have a guarantee that agrees to assume financial responsibility for the lease if the principal tenant cannot pay for any reason. Add a co-signer contract to your lease agreement to prove that a co-signer has agreed to assume financial responsibility if the tenant is unable to pay. As a tenant with an unstable job or a bad/no credit, a co-signed contract shows your landlord that rents are guaranteed. As a landlord, it ensures that another party pays for rent and other costs if the tenant cannot pay. As a co-signer, she exposes your legal and financial responsibility for rent on behalf of a tenant. Your co-signature contract should contain information such as: Who is the owner; The (s) name (s) of the (s) tenant (s); When the original lease was signed; The location of the rental property The co-signer`s name, driver`s license and social security number; If the co-signer is responsible for extending or modifying the lease; and all other special provisions. Other names for this document: Co-Signer Agreement Form, Lease Co-Signer Agreement Lease Cosigners, AKA Guarantors: Frequently Asked Questions.