What are the responsibilities of the guarantor on an apartment lease?

A guarantor is someone who has agreed to be legally bound to pay certain debts of another person if that other person does not, for any reason, pay his or her own debts. A guarantor of an apartment lease will be liable for the rent not paid by the tenant, as well as for any damage done and repairs not made by the tenant. Being a guarantor involves much more than simply being a reference for another person. Being a guarantor could end up costing someone thousands of dollars.