* Credit History: Landlords check credit scores. Students typically have limited or no credit history, making them higher risk. A co-signer with good credit mitigates this risk for the landlord.
* Income: Landlords usually require tenants to demonstrate sufficient income to cover the rent. Students often lack a consistent, substantial income stream. A co-signer's income can address this concern.
* Rental History: A lack of rental history makes a student a less predictable tenant. A co-signer with a positive rental history can help.
* Landlord's Policies: Some landlords have strict policies requiring co-signers for all tenants under a certain age or with limited credit history, regardless of individual circumstances. Others may be more flexible.
In short, while it's not legally *necessary* in all cases, a co-signer significantly improves a college student's chances of securing an apartment lease. Many landlords will simply refuse to rent to a student without one.