Does the mobile phone IOU have legal effect?

Legal analysis: IOUs can be proved by SMS. According to the Civil Code, the parties may conclude a contract in written form, oral form and other forms. If laws and administrative regulations stipulate that it should be in writing, it should be in writing. If the parties agree to use written form, it shall be in written form.

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

Article 469 The parties may conclude a contract in writing, orally or in other forms. Written form refers to contracts, letters, telegrams, telexes, faxes and other forms that can tangibly express the contents contained. A data message that can tangibly express its content through electronic data interchange, e-mail, etc. , and can be retrieved at any time, are considered in writing.

Article 668 A loan contract shall be in written form, unless otherwise agreed between natural persons. The contents of a loan contract generally include terms such as loan type, currency, purpose, amount, interest rate, term and repayment method.