Lease glossary

Cosigner

A cosigner is a person who signs the lease alongside the tenant and becomes equally responsible for the rent and every other lease obligation. Landlords ask for one when an applicant’s income or credit falls short of their screening standard.

Also called co-signer

Example

Jordan, 22, earns $3,600 a month and applies for a $1,400 apartment where the landlord wants income of 3 times the rent, or $4,200. Jordan’s parent cosigns the lease. If Jordan misses a month, the landlord can bill the full $1,400 to either of them, and a judgment for unpaid rent can name both. The lease says the cosigner has no right to live there, so the parent carries the risk without the apartment.

In a lease it looks like…

Co-Signer signs this Lease to secure Tenant’s obligations and is jointly and severally liable with Tenant for all rent, fees and damages. Co-Signer shall not occupy the premises.

Good to know

Cosigner and guarantor are often used for the same role. The practical difference is the paper: a cosigner signs the lease, a guarantor signs a separate guarantee, and either can be pursued for the whole debt. Before signing, ask whether the obligation continues if the lease renews.

Plain English, not legal advice. Last reviewed September 29, 2026.