The guarantor is responsible. If the lender can't pay back the money, he will ask you to help him pay it back. If you were the contact, there would be no such problem. At present, the general private lending company will always ask the lender for repayment at first, but if your friend really defaults, it is impossible for a private lending company like this to check his account like a bank, so it is very likely to find you. This kind of guarantee is generally more relatives, after all, know the root of the matter and guarantee some. As a general friend, I advise you not to guarantee. If he runs away, it's your turn to pay him back. Your signature is legally binding.