Fill out all applicable spaces in the information grid at the top of the front page of the Guarantee. SBA Lenders may use this form.This Secondary Participation Guaranty Agreement is a contract that details the terms and conditions of the sale of the guaranteed portion of an SBA loan. This Agreement supplements the Loan Guarantee Agreement, SBA Form 750, and, if applicable, SBA Form 750B (for shortterm loans), between Lender and SBA. What form(s) do I need to fill out? What document(s) do I need to bring? SBA Form 148 (Unconditional Guarantee) and SBA Form 148L (Limited Guarantee) are the standard documents for providing a guaranty on an SBA loan. What Is a Guarantor? In the context of business loans, a guarantor is a person who agrees to repay the loan if the business is unable to do so. The parties to this Agreement accept all the provisions of the General Conditions Applicable to Loan and.