When you open a small business, you’re not the only one taking a huge financial risk – your credit card issuer is, too. To minimize losses in the event that your company fails, lenders generally require you to sign a personal guarantee and provide your Social Security number when you apply for a business credit card. Here’s what that means for you. What is a personal guarantee? A personal guarantee is an agreement you make with your creditor to personally pay your business’s debts if your company doesn’t.