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.Middlesex Savings Bank in MA offers SBA financing that can get your business off the ground. Contact or visit your nearest branch location to learn more. 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. Personal guarantees in Massachusetts are strictly enforced according to their contractual provisions. Their enforcement is favored as a matter of public policy. 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.