How to write an iou to have legal effect? Can't the other party sue if it has always owed money?

1. IOUs established according to law have legal effect. In general, the following contents need to be stated in the written IOU:

1. Legal full names of debtors and creditors;

2, the specific time and reason of arrears;

3. The amount owed, including the amount in words and figures;

4. The specific time and payment method of repayment;

5. Liability for breach of contract for overdue repayment;

6. Finally, the debtor shall sign, seal or fingerprint.

2. Can the other party sue if it has always owed money?

If the other party has been in arrears and cannot repay the lawsuit, if the borrower fails to repay the lawsuit within the time limit, the parties concerned shall bring a public prosecution to the people's court with jurisdiction.

Legal basis:

Provisions of the Supreme People's Court on Several Issues Concerning the Application of Laws in the Trial of Private Lending Cases Article 2 When a lender brings a private lending lawsuit to a people's court, it shall provide creditor's rights certificates such as IOUs, receipts, IOUs and other evidence that can prove the existence of the legal relationship between lending and borrowing.

If the creditor's rights certificate such as IOUs, receipts and IOUs held by the parties does not specify the creditor, and the party holding the creditor's rights certificate brings a private lending lawsuit, the people's court shall accept it. The defendant raised a factual defense against the plaintiff's creditor qualification, and the people's court ruled that the plaintiff did not have the creditor qualification after examination and dismissed the prosecution.

Article 21 of the Civil Procedure Law of People's Republic of China (PRC)? A civil action brought against a citizen shall be under the jurisdiction of the people's court of the defendant's domicile; If the defendant's domicile is inconsistent with his habitual residence, it shall be under the jurisdiction of the people's court of habitual residence. A civil lawsuit brought against a legal person or other organization shall be under the jurisdiction of the people's court where the defendant is domiciled. Where the domiciles and habitual residences of several defendants in the same lawsuit are under the jurisdiction of two or more people's courts, they shall be under the jurisdiction of each people's court.