Legal analysis: If you lend your credit card to someone else without an IOU, it is recommended to collect evidence and prosecute. The IOU is an important documentary evidence of the existence of a loan relationship and a certificate of creditor's rights, but it is not the only evidence. In the absence of an IOU, the lender can prove the existence of the loan relationship through text message records, call recordings, bank transfer vouchers, witness testimony and other evidence of communication between the borrower and the lender regarding the loan. If a chain of evidence is formed, the court will rule that the loan relationship exists and the loan People should repay.

Legal basis: Article 668 of the "People's Republic of China and Civil Code" A loan contract shall be in writing, except where there is a separate agreement on the loan between natural persons. The content of a loan contract generally includes terms such as loan type, currency, purpose, amount, interest rate, term and repayment method.