Legal analysis: 1. Before the bank lends money, it should write an IOU to the bank. 2. Signing a loan contract with the bank only shows that the two parties have reached an agreement on the loan, which does not mean that the bank will give the loan to the lender, that is, it does not mean that the borrower has received the loan from the bank. IOUs are evidence that banks issue loans to borrowers. The IOU knowledge of bank loans shows how many loans the bank gave to the borrower on xx, xx, xx, and also shows that the borrower received the loan from the bank. It can be seen that there should be IOUs.

Legal basis: Article 24 of the Working Capital Loan Measures of the People's Construction Bank of China. If the borrower cannot repay the loan on time due to special reasons, he shall submit a written application for extension to the Construction Bank fifteen days in advance, and the Construction Bank may decide whether to extend the loan according to the situation; If the loan extension is approved after examination, an extension repayment agreement shall be signed. If the original loan is a guaranteed loan, mortgage loan or pledge loan, the guarantor, mortgagor and pledger shall issue a written certificate (or renew the corresponding contract) agreeing to the extension. Extend the deadline once. If the borrower's written application for loan extension is not approved, the borrower shall repay the loan on schedule. When the extended loan expires, the borrower shall repay the loan on schedule.