Legal analysis: A surety contract is a contract in which the surety and the creditor agree that when the debtor fails to perform the due debt or the circumstances agreed by the parties occur, the surety will perform the debt or assume the responsibility. In a suretyship contract, if the parties agree that the effectiveness of the suretyship contract is independent of the main contract, or that the guarantor is liable for the legal consequences of the invalidity of the main contract, the agreement on the independence of suretyship is invalid. If the main contract is valid, the agreement on ensuring independence is invalid and does not affect the effectiveness of the guarantee contract; If the main contract is invalid, the people's court shall consider the guarantee contract invalid, except as otherwise provided by law.

Legal basis: Civil Code of People's Republic of China (PRC).

Article 681 A suretyship contract is a contract in which the surety and the creditor agree that the surety will perform the debt or assume the liability when the debtor fails to perform the due debt or the circumstances agreed by the parties occur.

Article 682 A suretyship contract is an accessory contract to the principal creditor's rights and debts contract. If the principal creditor's rights and debts contract is invalid, the guarantee contract is invalid, unless otherwise stipulated by law. If the debtor, guarantor and creditor are at fault after the guaranty contract is confirmed to be invalid, they shall bear corresponding civil liabilities according to their faults.

Article 683 A legal person organ shall not act as a guarantor, except for the use of loans from foreign governments or international economic organizations with the approval of the State Council. A legal person not for profit or an unincorporated organization for public welfare may not act as a guarantor.

Article 684 The contents of a suretyship contract generally include the type and amount of the principal creditor's rights to be secured, the time limit for the debtor to perform the debt, the way, scope and period of suretyship, etc.

Article 685 A suretyship contract may be a separate written contract or a suretyship clause in the principal creditor's rights and debts contract. If the third party unilaterally makes a written guarantee to the creditor, and the creditor accepts it without raising any objection, the guarantee contract is established.