A personal guarantee is a contractual commitment by an individual — typically the business owner — to be personally responsible for a business debt if the business defaults. Understanding exactly what you are guaranteeing, and the limits (if any) of that guarantee, is one of the most important readings before signing any commercial loan document.
Full (unlimited) personal guarantee: The guarantor is responsible for the full outstanding loan balance at default, plus any accrued interest, fees, collection costs, and legal expenses. Most commercial loans include full personal guarantees. If the business fails and the collateral is insufficient to repay the loan, the lender can sue the guarantor personally and seek judgment against personal assets — savings accounts, personal real estate, investment accounts, and other personal property.
Limited personal guarantee: Limits the guarantor's liability to a specific dollar amount or a specific percentage of the outstanding balance. Uncommon on small business loans but more frequent in larger commercial transactions. A guarantor with a $500,000 limited guarantee on a $2 million loan is responsible for up to $500,000 of deficiency but no more, regardless of what the business owes at default.
Spousal guarantee: In community property states (California, Texas, Arizona, Nevada, Washington, and others), lenders may require a spouse to co-sign the personal guarantee if a significant portion of the guarantor's assets are held jointly. Spouses who are not involved in the business should understand what they are signing before executing a spousal guarantee.
Guarantee burn-down: Some loan agreements include provisions where the personal guarantee reduces as the loan is paid down — for example, the guarantor's liability drops from 100% to 50% after the first 3 years of payments. These are not standard but are worth negotiating for on larger transactions.