A guarantor is someone who cosigns the lease agreement and is responsible for any rent payments that you cannot or do not make. Even with a guarantor lease, the tenant (the person living there) must both fill out an application.Guarantor: Gross monthly income must meet or exceed four times the monthly rent amount. A lease guarantor is an individual who accepts financial responsibility if a tenant defaults on the lease agreement. I came across using a rent guarantor company. A second chance to secure your dream home. Helping you qualify for the rental you want, while giving property managers protection against defaults. Fill out the lease guaranty application online and send us your paperwork. Draft CoSign Lease Form A lease guarantor form should be presented to the tenant and guarantor for review. Filling places with people makes everyone happy.