A guarantor is a person with good credit who agrees to co-sign, or sign on behalf of someone else, and be responsible for the rented space, its condition, the rent and any fees that may be incurred over the rental period.
Landlords want to be sure that their tenants are responsible, will care for the unit and will be timely with rental payments. If your credit history is weak or too short to have established your credit-worthiness, a potential landlord may be hesitant to allow you to rent from him or her. A guarantor can solve this problem by guaranteeing to the landlord that if you're unable to pay for rent or repairs, it will still be taken care of.
Because co-signing for someone could be risky when it's for someone with bad or unreliable credit, it's best to ask family members or close friends who trust you and know you well to be your guarantor.
Landlords or property managers are more likely to accept applications with guarantors who are close to potential tenants, so they know it will be easy to collect payment from them in case the tenant doesn't pay.
Guarantors can help poor applicants get into rental properties they otherwise wouldn't. If you know your rental or credit history needs some work before it would qualify you for the housing you want, see if you can get a family member to be your guarantor.