Is such an IOU valid? What kind of IOUs are valid?

There are some provisions in the civil law, I hope it will be helpful to you.

A contract that violates the true intention of the civil subject is invalid.

If the parties to the contract collude to harm the interests of a third party, the contract shall be invalid.

A contract that is a material misunderstanding and manifestly unfair is a voidable contract, and the parties may apply to the people's court for revocation.

The key is that C can prove that A and B have conspired to harm his interests and that C was unaware of the situation before entering into the contract.

As long as it is signed, it has legal effect.

If you feel cheated, then you can call the police immediately, and a case will be opened for investigation. If it is found out that you have indeed been deceived, it is invalid to change the IOU.

If it is really a partnership to deceive her, it is recommended that it is best to call the police, if it is found out that it is indeed a deception to you, the IOU will be invalid. And A and B will also be punished by law.

The guarantor's liability on the IOU is to be liable only if the borrower is unable to repay the debt. Of course, it is also possible to recover from the borrower. According to Chinese law, if the guarantor can prove that he is a fraud, he can sue the court. The guarantor itself is not liable for repayment.

Legal and valid IOUs have the following precautions: 1. Write the full legal names of the borrower and lender clearly, and it is better to attach an ID number. 2. Write down the amount of the loan, including the uppercase and lowercase amount.

3. Write down the time limit of the loan, including the start and end date of the loan and the clear loan term. 4. Write down the interest of the loan and the payment method, etc. 5. Both parties have the corresponding capacity for civil conduct.

[Legal basis].

Article 18 of the Civil Code provides that adults are persons with full capacity for civil conduct and may independently carry out civil juristic acts. Minors over the age of 16 who rely on their own labor income as their main livelihood** are to be regarded as persons with full capacity for civil conduct. Article 668:The loan contract shall be in written form, unless otherwise agreed upon between natural persons.

The content of the loan contract generally includes the type of loan, currency, purpose, amount, interest rate, term and repayment method.

Legal Analysis: A valid IOU generally needs to state the following:

1. The full legal names of the debtor and the creditor;

2. The specific time and reason for the arrears of the debtor;

3. The amount owed, including uppercase and lowercase amounts;

4. The specific time and payment method of repayment;

5. Liability for breach of contract for overdue repayment;

6. Finally, the arrears shall be stamped, fingerprinted or signed.

Legal basis: Civil Code of the People's Republic of China Article 502 A contract established in accordance with law shall take effect upon its establishment, unless otherwise provided by law or otherwise agreed by the parties. In accordance with the provisions of laws and administrative regulations, if the contract shall go through formalities such as approval, follow those provisions.

If the failure to go through formalities such as approval affects the effectiveness of the contract, it does not affect the validity of the provisions of the contract on the performance of obligations such as reporting for approval and the validity of the relevant clauses. If a party who should go through formalities such as applying for approval fails to perform its obligations, the other party may request that it bear responsibility for violating such obligations. Where, in accordance with the provisions of laws and administrative regulations, the modification, transfer, or termination of a contract shall go through formalities such as approval, the provisions of the preceding paragraph shall apply.