Co-signers can be helpful since they can fill vacancies more quickly, which is beneficial, especially when the rental market is competitive. When do I need a cosigner?Learn the essential steps on how to add a cosigner to a lease to strengthen your rental agreement. CO-SIGNER: A co-signer can be an alternate way of being approved to rent a property from Utah Management. Cosigners take on financial responsibility if you are unable to pay your rent, so be mindful that this is a huge commitment for them. As a co-signer, you don't have to live in the apartment but your name will be on the lease and you'll be legally obligated to follow the terms of the lease. No matter where you live, always make sure you understand the terms of your lease before signing! 1. Create an Account 2. A cosigner is a person who signs your apartment lease and shares responsibility for rental payments. The cosigner agrees to pay your rent if you can't.