A personal guarantee commercial lease is a legally abiding contract that makes a business owner assume personal liability for responsibilities and obligations. Understand personal guarantee commercial lease agreements and protect your interests.In almost every commercial lease situation, the landlord should insist on a personal guarantee from the owner of the tenant. The personal guarantee in a commercial lease makes you, the tenant, personally liable for any rent your business's profits cannot cover. The landlord requires that I sign a personal guarantee, or provide a 6-month security deposit, to lease the space. Download free Utah commercial lease agreement template online. These forms are fillable, printable, and available as PDF or WORD documents. A personal guarantee on a commercial lease means that an individual promised to complete the terms of the commercial lease even if the business were to close.